diff --git a/app/assets/javascripts/vue_merge_request_widget/components/deployment.vue b/app/assets/javascripts/vue_merge_request_widget/components/deployment.vue
index 9161f703697..6c87287a4c4 100644
--- a/app/assets/javascripts/vue_merge_request_widget/components/deployment.vue
+++ b/app/assets/javascripts/vue_merge_request_widget/components/deployment.vue
@@ -1,6 +1,7 @@
 <script>
 import Icon from '~/vue_shared/components/icon.vue';
 import TooltipOnTruncate from '~/vue_shared/components/tooltip_on_truncate.vue';
+import FilteredSearchDropdown from '~/vue_shared/components/filtered_search_dropdown.vue';
 import timeagoMixin from '../../vue_shared/mixins/timeago';
 import tooltip from '../../vue_shared/directives/tooltip';
 import LoadingButton from '../../vue_shared/components/loading_button.vue';
@@ -18,6 +19,7 @@ export default {
     StatusIcon,
     Icon,
     TooltipOnTruncate,
+    FilteredSearchDropdown,
   },
   directives: {
     tooltip,
@@ -30,8 +32,10 @@ export default {
     },
   },
   data() {
+    const features = window.gon.features || {};
     return {
       isStopping: false,
+      enableCiEnvironmentsStatusChanges: features.ciEnvironmentsStatusChanges,
     };
   },
   computed: {
@@ -118,18 +122,65 @@ export default {
             />
           </div>
           <div>
-            <a
-              v-if="hasExternalUrls"
-              :href="deployment.external_url"
-              target="_blank"
-              rel="noopener noreferrer nofollow"
-              class="deploy-link js-deploy-url btn btn-default btn-sm inline"
-            >
-              <span>
-                View app
-                <icon name="external-link" />
-              </span>
-            </a>
+            <template v-if="hasExternalUrls">
+              <filtered-search-dropdown
+                v-if="enableCiEnvironmentsStatusChanges"
+                class="js-mr-wigdet-deployment-dropdown inline"
+                :items="deployment.changes"
+                :main-action-link="deployment.external_url"
+                filter-key="path"
+              >
+                <template
+                  slot="mainAction"
+                  slot-scope="slotProps"
+                >
+                  <a
+                    :href="deployment.external_url"
+                    target="_blank"
+                    rel="noopener noreferrer nofollow"
+                    class="deploy-link js-deploy-url inline"
+                    :class="slotProps.className"
+                  >
+                    <span>
+                      {{ __('View app') }}
+                      <icon name="external-link" />
+                    </span>
+                  </a>
+                </template>
+
+                <template
+                  slot="result"
+                  slot-scope="slotProps"
+                >
+                  <a
+                    :href="slotProps.result.external_url"
+                    target="_blank"
+                    rel="noopener noreferrer nofollow"
+                    class="menu-item"
+                  >
+                    <strong class="str-truncated-100 append-bottom-0 d-block">
+                      {{ slotProps.result.path }}
+                    </strong>
+
+                    <p class="text-secondary str-truncated-100 append-bottom-0 d-block">
+                      {{ slotProps.result.external_url }}
+                    </p>
+                  </a>
+                </template>
+              </filtered-search-dropdown>
+              <a
+                v-else
+                :href="deployment.external_url"
+                target="_blank"
+                rel="noopener noreferrer nofollow"
+                class="js-deploy-url js-deploy-url-feature-flag deploy-link btn btn-default btn-sm inline"
+              >
+                <span>
+                  {{ __('View app') }}
+                  <icon name="external-link" />
+                </span>
+              </a>
+            </template>
             <loading-button
               v-if="deployment.stop_url"
               :loading="isStopping"
diff --git a/app/assets/javascripts/vue_merge_request_widget/mr_widget_options.vue b/app/assets/javascripts/vue_merge_request_widget/mr_widget_options.vue
index a599cc002d6..8180f13a7cb 100644
--- a/app/assets/javascripts/vue_merge_request_widget/mr_widget_options.vue
+++ b/app/assets/javascripts/vue_merge_request_widget/mr_widget_options.vue
@@ -112,7 +112,8 @@ export default {
     eventHub.$on('mr.discussion.updated', this.checkStatus);
   },
   mounted() {
-    this.handleMounted();
+    this.setFaviconHelper();
+    this.initDeploymentsPolling();
   },
   beforeDestroy() {
     eventHub.$off('mr.discussion.updated', this.checkStatus);
@@ -250,10 +251,6 @@ export default {
         this.stopPolling();
       });
     },
-    handleMounted() {
-      this.setFaviconHelper();
-      this.initDeploymentsPolling();
-    },
   },
 };
 </script>
diff --git a/app/assets/javascripts/vue_shared/components/filtered_search_dropdown.vue b/app/assets/javascripts/vue_shared/components/filtered_search_dropdown.vue
new file mode 100644
index 00000000000..460fa6ad72e
--- /dev/null
+++ b/app/assets/javascripts/vue_shared/components/filtered_search_dropdown.vue
@@ -0,0 +1,143 @@
+<script>
+import $ from 'jquery';
+import Icon from '~/vue_shared/components/icon.vue';
+/**
+ * Renders a split dropdown with
+ * an input that allows to search through the given
+ * array of options.
+ */
+export default {
+  name: 'FilteredSearchDropdown',
+  components: {
+    Icon,
+  },
+  props: {
+    title: {
+      type: String,
+      required: false,
+      default: '',
+    },
+    buttonType: {
+      required: false,
+      validator: value =>
+        ['primary', 'default', 'secondary', 'success', 'info', 'warning', 'danger'].indexOf(
+          value,
+        ) !== -1,
+      default: 'default',
+    },
+    size: {
+      required: false,
+      type: String,
+      default: 'sm',
+    },
+    items: {
+      type: Array,
+      required: true,
+    },
+    visibleItems: {
+      type: Number,
+      required: false,
+      default: 5,
+    },
+    filterKey: {
+      type: String,
+      required: true,
+    },
+  },
+  data() {
+    return {
+      filter: '',
+    };
+  },
+  computed: {
+    className() {
+      return `btn btn-${this.buttonType} btn-${this.size}`;
+    },
+    filteredResults() {
+      if (this.filter !== '') {
+        return this.items.filter(
+          item => item[this.filterKey] && item[this.filterKey].toLowerCase().includes(this.filter.toLowerCase()),
+        );
+      }
+
+      return this.items.slice(0, this.visibleItems);
+    }
+  },
+  mounted() {
+    /**
+     * Resets the filter every time the user closes the dropdown
+     */
+    $(this.$el)
+      .on('shown.bs.dropdown', () => {
+        this.$nextTick(() => this.$refs.searchInput.focus());
+      })
+      .on('hidden.bs.dropdown', () => {
+        this.filter = '';
+      });
+  },
+};
+</script>
+<template>
+  <div class="dropdown">
+    <div class="btn-group">
+      <slot
+        name="mainAction"
+        :class-name="className"
+      >
+        <button
+          type="button"
+          :class="className"
+        >
+          {{ title }}
+        </button>
+      </slot>
+
+      <button
+        type="button"
+        :class="className"
+        class="dropdown-toggle dropdown-toggle-split"
+        data-toggle="dropdown"
+        aria-haspopup="true"
+        aria-expanded="false"
+        aria-label="Expand dropdown"
+      >
+        <icon
+          name="angle-down"
+          :size="12"
+        />
+      </button>
+      <div class="dropdown-menu dropdown-menu-right">
+        <div class="dropdown-input">
+          <input
+            ref="searchInput"
+            v-model="filter"
+            type="search"
+            placeholder="Filter"
+            class="js-filtered-dropdown-input dropdown-input-field"
+          />
+          <icon
+            class="dropdown-input-search"
+            name="search"
+          />
+        </div>
+
+        <div class="dropdown-content">
+          <ul>
+            <li
+              v-for="(result, i) in filteredResults"
+              :key="i"
+              class="js-filtered-dropdown-result"
+            >
+              <slot
+                name="result"
+                :result="result"
+              >
+                {{ result[filterKey] }}
+              </slot>
+            </li>
+          </ul>
+        </div>
+      </div>
+    </div>
+  </div>
+</template>
diff --git a/app/assets/stylesheets/pages/merge_requests.scss b/app/assets/stylesheets/pages/merge_requests.scss
index 895db89f289..2feb7464ecb 100644
--- a/app/assets/stylesheets/pages/merge_requests.scss
+++ b/app/assets/stylesheets/pages/merge_requests.scss
@@ -47,7 +47,6 @@
   }
 }
 
-
 .mr-widget-heading {
   position: relative;
   border: 1px solid $border-color;
@@ -454,7 +453,7 @@
 
 .mr-list {
   .merge-request {
-    padding: 10px  0 10px 15px;
+    padding: 10px 0 10px 15px;
     position: relative;
     display: -webkit-flex;
     display: flex;
@@ -468,7 +467,6 @@
       margin-bottom: 2px;
 
       .ci-status-link {
-
         svg {
           height: 16px;
           width: 16px;
@@ -698,7 +696,6 @@
 
 .table-holder {
   .ci-table {
-
     th {
       background-color: $white-light;
       color: $gl-text-color-secondary;
@@ -775,7 +772,7 @@
 
   &.affix {
     left: 0;
-    transition: right .15s;
+    transition: right 0.15s;
 
     @include media-breakpoint-down(xs) {
       right: 0;
@@ -884,7 +881,7 @@
   }
 
   > *:not(:last-child) {
-    margin-right: .3em;
+    margin-right: 0.3em;
   }
 
   svg {
@@ -907,6 +904,10 @@
   .btn svg {
     fill: $theme-gray-700;
   }
+
+  .dropdown-menu {
+    width: 400px;
+  }
 }
 
 // Hack alert: we've rewritten `btn` class in a way that
@@ -917,7 +918,7 @@
   &[disabled] {
     cursor: not-allowed;
     box-shadow: none;
-    opacity: .65;
+    opacity: 0.65;
 
     &:hover {
       color: $gl-gray-500;
diff --git a/app/controllers/projects/merge_requests_controller.rb b/app/controllers/projects/merge_requests_controller.rb
index f87337b67aa..757b03d0b0e 100644
--- a/app/controllers/projects/merge_requests_controller.rb
+++ b/app/controllers/projects/merge_requests_controller.rb
@@ -14,6 +14,9 @@ class Projects::MergeRequestsController < Projects::MergeRequests::ApplicationCo
   before_action :set_issuables_index, only: [:index]
   before_action :authenticate_user!, only: [:assign_related_issues]
   before_action :check_user_can_push_to_source_branch!, only: [:rebase]
+  before_action do
+    push_frontend_feature_flag(:ci_environments_status_changes)
+  end
 
   def index
     @merge_requests = @issuables
diff --git a/changelogs/unreleased/fe-ac-review-app-changes-33418.yml b/changelogs/unreleased/fe-ac-review-app-changes-33418.yml
new file mode 100644
index 00000000000..e4803683062
--- /dev/null
+++ b/changelogs/unreleased/fe-ac-review-app-changes-33418.yml
@@ -0,0 +1,5 @@
+---
+title: Adds filtered dropdown with changed files in review
+merge_request:
+author:
+type: changed
diff --git a/locale/gitlab.pot b/locale/gitlab.pot
index d73beaf93b6..bb18d4eccd8 100644
--- a/locale/gitlab.pot
+++ b/locale/gitlab.pot
@@ -6717,6 +6717,9 @@ msgstr ""
 msgid "Version"
 msgstr ""
 
+msgid "View app"
+msgstr ""
+
 msgid "View file @ "
 msgstr ""
 
diff --git a/spec/javascripts/vue_mr_widget/components/deployment_spec.js b/spec/javascripts/vue_mr_widget/components/deployment_spec.js
index 20b5532a837..ce850bc621e 100644
--- a/spec/javascripts/vue_mr_widget/components/deployment_spec.js
+++ b/spec/javascripts/vue_mr_widget/components/deployment_spec.js
@@ -14,6 +14,20 @@ const deploymentMockData = {
   external_url_formatted: 'diplo.',
   deployed_at: '2017-03-22T22:44:42.258Z',
   deployed_at_formatted: 'Mar 22, 2017 10:44pm',
+  changes: [
+    {
+      path: 'index.html',
+      external_url: 'http://root-master-patch-91341.volatile-watch.surge.sh/index.html',
+    },
+    {
+      path: 'imgs/gallery.html',
+      external_url: 'http://root-master-patch-91341.volatile-watch.surge.sh/imgs/gallery.html',
+    },
+    {
+      path: 'about/',
+      external_url: 'http://root-master-patch-91341.volatile-watch.surge.sh/about/',
+    },
+  ],
 };
 const createComponent = () => {
   const Component = Vue.extend(deploymentComponent);
@@ -176,4 +190,42 @@ describe('Deployment component', () => {
       expect(el.querySelector('.js-mr-memory-usage')).not.toBeNull();
     });
   });
+
+  describe('with `features.ciEnvironmentsStatusChanges` enabled', () => {
+    beforeEach(() => {
+      window.gon = window.gon || {};
+      window.gon.features = window.gon.features || {};
+      window.gon.features.ciEnvironmentsStatusChanges = true;
+
+      vm = createComponent(deploymentMockData);
+    });
+
+    afterEach(() => {
+      window.gon.features = {};
+    });
+
+    it('renders dropdown with changes', () => {
+      expect(vm.$el.querySelector('.js-mr-wigdet-deployment-dropdown')).not.toBeNull();
+      expect(vm.$el.querySelector('.js-deploy-url-feature-flag')).toBeNull();
+    });
+  });
+
+  describe('with `features.ciEnvironmentsStatusChanges` disabled', () => {
+    beforeEach(() => {
+      window.gon = window.gon || {};
+      window.gon.features = window.gon.features || {};
+      window.gon.features.ciEnvironmentsStatusChanges = false;
+
+      vm = createComponent(deploymentMockData);
+    });
+
+    afterEach(() => {
+      delete window.gon.features.ciEnvironmentsStatusChanges;
+    });
+
+    it('renders the old link to the review app', () => {
+      expect(vm.$el.querySelector('.js-mr-wigdet-deployment-dropdown')).toBeNull();
+      expect(vm.$el.querySelector('.js-deploy-url-feature-flag')).not.toBeNull();
+    });
+  });
 });
diff --git a/spec/javascripts/vue_mr_widget/mr_widget_options_spec.js b/spec/javascripts/vue_mr_widget/mr_widget_options_spec.js
index 6b5e32fdfd5..d1a064b9f4d 100644
--- a/spec/javascripts/vue_mr_widget/mr_widget_options_spec.js
+++ b/spec/javascripts/vue_mr_widget/mr_widget_options_spec.js
@@ -7,11 +7,12 @@ import mountComponent from 'spec/helpers/vue_mount_component_helper';
 import mockData from './mock_data';
 import { faviconDataUrl, overlayDataUrl, faviconWithOverlayDataUrl } from '../lib/utils/mock_data';
 
-const returnPromise = data => new Promise((resolve) => {
-  resolve({
-    data,
+const returnPromise = data =>
+  new Promise(resolve => {
+    resolve({
+      data,
+    });
   });
-});
 
 describe('mrWidgetOptions', () => {
   let vm;
@@ -135,7 +136,7 @@ describe('mrWidgetOptions', () => {
 
   describe('methods', () => {
     describe('checkStatus', () => {
-      it('should tell service to check status', (done) => {
+      it('should tell service to check status', done => {
         spyOn(vm.service, 'checkStatus').and.returnValue(returnPromise(mockData));
         spyOn(vm.mr, 'setData');
         spyOn(vm, 'handleNotification');
@@ -185,7 +186,7 @@ describe('mrWidgetOptions', () => {
     });
 
     describe('fetchDeployments', () => {
-      it('should fetch deployments', (done) => {
+      it('should fetch deployments', done => {
         spyOn(vm.service, 'fetchDeployments').and.returnValue(returnPromise([{ id: 1 }]));
 
         vm.fetchDeployments();
@@ -200,7 +201,7 @@ describe('mrWidgetOptions', () => {
     });
 
     describe('fetchActionsContent', () => {
-      it('should fetch content of Cherry Pick and Revert modals', (done) => {
+      it('should fetch content of Cherry Pick and Revert modals', done => {
         spyOn(vm.service, 'fetchMergeActionsContent').and.returnValue(returnPromise('hello world'));
 
         vm.fetchActionsContent();
@@ -251,7 +252,7 @@ describe('mrWidgetOptions', () => {
         };
 
         const allArgs = eventHub.$on.calls.allArgs();
-        allArgs.forEach((params) => {
+        allArgs.forEach(params => {
           const eventName = params[0];
           const callback = params[1];
 
@@ -270,18 +271,6 @@ describe('mrWidgetOptions', () => {
       });
     });
 
-    describe('handleMounted', () => {
-      it('should call required methods to do the initial kick-off', () => {
-        spyOn(vm, 'initDeploymentsPolling');
-        spyOn(vm, 'setFaviconHelper');
-
-        vm.handleMounted();
-
-        expect(vm.setFaviconHelper).toHaveBeenCalled();
-        expect(vm.initDeploymentsPolling).toHaveBeenCalled();
-      });
-    });
-
     describe('setFavicon', () => {
       let faviconElement;
 
@@ -298,13 +287,14 @@ describe('mrWidgetOptions', () => {
         document.body.removeChild(document.getElementById('favicon'));
       });
 
-      it('should call setFavicon method', (done) => {
+      it('should call setFavicon method', done => {
         vm.mr.ciStatusFaviconPath = overlayDataUrl;
-        vm.setFaviconHelper().then(() => {
-          expect(faviconElement.getAttribute('href')).toEqual(faviconWithOverlayDataUrl);
-          done();
-        })
-        .catch(done.fail);
+        vm.setFaviconHelper()
+          .then(() => {
+            expect(faviconElement.getAttribute('href')).toEqual(faviconWithOverlayDataUrl);
+            done();
+          })
+          .catch(done.fail);
       });
 
       it('should not call setFavicon when there is no ciStatusFaviconPath', () => {
@@ -379,7 +369,7 @@ describe('mrWidgetOptions', () => {
   });
 
   describe('rendering relatedLinks', () => {
-    beforeEach((done) => {
+    beforeEach(done => {
       vm.mr.relatedLinks = {
         assignToMe: null,
         closing: `
@@ -396,7 +386,7 @@ describe('mrWidgetOptions', () => {
       expect(vm.$el.querySelector('.close-related-link')).toBeDefined();
     });
 
-    it('does not render if state is nothingToMerge', (done) => {
+    it('does not render if state is nothingToMerge', done => {
       vm.mr.state = stateKey.nothingToMerge;
       Vue.nextTick(() => {
         expect(vm.$el.querySelector('.close-related-link')).toBeNull();
@@ -406,7 +396,7 @@ describe('mrWidgetOptions', () => {
   });
 
   describe('rendering source branch removal status', () => {
-    it('renders when user cannot remove branch and branch should be removed', (done) => {
+    it('renders when user cannot remove branch and branch should be removed', done => {
       vm.mr.canRemoveSourceBranch = false;
       vm.mr.shouldRemoveSourceBranch = true;
       vm.mr.state = 'readyToMerge';
@@ -423,7 +413,7 @@ describe('mrWidgetOptions', () => {
       });
     });
 
-    it('does not render in merged state', (done) => {
+    it('does not render in merged state', done => {
       vm.mr.canRemoveSourceBranch = false;
       vm.mr.shouldRemoveSourceBranch = true;
       vm.mr.state = 'merged';
@@ -438,6 +428,20 @@ describe('mrWidgetOptions', () => {
   });
 
   describe('rendering deployments', () => {
+    const changes = [
+      {
+        path: 'index.html',
+        external_url: 'http://root-master-patch-91341.volatile-watch.surge.sh/index.html',
+      },
+      {
+        path: 'imgs/gallery.html',
+        external_url: 'http://root-master-patch-91341.volatile-watch.surge.sh/imgs/gallery.html',
+      },
+      {
+        path: 'about/',
+        external_url: 'http://root-master-patch-91341.volatile-watch.surge.sh/about/',
+      },
+    ];
     const deploymentMockData = {
       id: 15,
       name: 'review/diplo',
@@ -449,15 +453,23 @@ describe('mrWidgetOptions', () => {
       external_url_formatted: 'diplo.',
       deployed_at: '2017-03-22T22:44:42.258Z',
       deployed_at_formatted: 'Mar 22, 2017 10:44pm',
+      changes,
     };
 
-    beforeEach((done) => {
-      vm.mr.deployments.push({
-        ...deploymentMockData,
-      }, {
-        ...deploymentMockData,
-        id: deploymentMockData.id + 1,
-      });
+    beforeEach(done => {
+      window.gon = window.gon || {};
+      window.gon.features = window.gon.features || {};
+      window.gon.features.ciEnvironmentsStatusChanges = true;
+
+      vm.mr.deployments.push(
+        {
+          ...deploymentMockData,
+        },
+        {
+          ...deploymentMockData,
+          id: deploymentMockData.id + 1,
+        },
+      );
 
       vm.$nextTick(done);
     });
@@ -465,5 +477,13 @@ describe('mrWidgetOptions', () => {
     it('renders multiple deployments', () => {
       expect(vm.$el.querySelectorAll('.deploy-heading').length).toBe(2);
     });
+
+    it('renders dropdpown with multiple file changes', () => {
+      expect(
+        vm.$el
+          .querySelector('.js-mr-wigdet-deployment-dropdown')
+          .querySelectorAll('.js-filtered-dropdown-result').length,
+      ).toEqual(changes.length);
+    });
   });
 });
diff --git a/spec/javascripts/vue_shared/components/filtered_search_dropdown_spec.js b/spec/javascripts/vue_shared/components/filtered_search_dropdown_spec.js
new file mode 100644
index 00000000000..b71cb36ecf6
--- /dev/null
+++ b/spec/javascripts/vue_shared/components/filtered_search_dropdown_spec.js
@@ -0,0 +1,91 @@
+import Vue from 'vue';
+import component from '~/vue_shared/components/filtered_search_dropdown.vue';
+import mountComponent from 'spec/helpers/vue_mount_component_helper';
+
+describe('Filtered search dropdown', () => {
+  const Component = Vue.extend(component);
+  let vm;
+
+  afterEach(() => {
+    vm.$destroy();
+  });
+
+  describe('with an empty array of items', () => {
+    beforeEach(() => {
+      vm = mountComponent(Component, {
+        items: [],
+        filterKey: '',
+      });
+    });
+
+    it('renders empty list', () => {
+      expect(vm.$el.querySelectorAll('.js-filtered-dropdown-result').length).toEqual(0);
+    });
+
+    it('renders filter input', () => {
+      expect(vm.$el.querySelector('.js-filtered-dropdown-input')).not.toBeNull();
+    });
+  });
+
+  describe('when visible numbers is less than the items length', () => {
+    beforeEach(() => {
+      vm = mountComponent(Component, {
+        items: [{ title: 'One' }, { title: 'Two' }, { title: 'Three' }],
+        visibleItems: 2,
+        filterKey: 'title',
+      });
+    });
+
+    it('it renders only the maximum number provided', () => {
+      expect(vm.$el.querySelectorAll('.js-filtered-dropdown-result').length).toEqual(2);
+    });
+  });
+
+  describe('when visible number is bigger than the items lenght', () => {
+    beforeEach(() => {
+      vm = mountComponent(Component, {
+        items: [{ title: 'One' }, { title: 'Two' }, { title: 'Three' }],
+        filterKey: 'title',
+      });
+    });
+
+    it('it renders the full list of items the maximum number provided', () => {
+      expect(vm.$el.querySelectorAll('.js-filtered-dropdown-result').length).toEqual(3);
+    });
+  });
+
+  describe('while filtering', () => {
+    beforeEach(() => {
+      vm = mountComponent(Component, {
+        items: [
+          { title: 'One' },
+          { title: 'Two/three' },
+          { title: 'Three four' },
+          { title: 'Five' },
+        ],
+        filterKey: 'title',
+      });
+    });
+
+    it('updates the results to match the typed value', done => {
+      vm.$el.querySelector('.js-filtered-dropdown-input').value = 'three';
+      vm.$el.querySelector('.js-filtered-dropdown-input').dispatchEvent(new Event('input'));
+      vm.$nextTick(() => {
+        expect(vm.$el.querySelectorAll('.js-filtered-dropdown-result').length).toEqual(2);
+        done();
+      });
+    });
+
+    describe('when no value matches the typed one', () => {
+      it('does not render any result', done => {
+        vm.$el.querySelector('.js-filtered-dropdown-input').value = 'six';
+        vm.$el.querySelector('.js-filtered-dropdown-input').dispatchEvent(new Event('input'));
+
+        vm.$nextTick(() => {
+          expect(vm.$el.querySelectorAll('.js-filtered-dropdown-result').length).toEqual(0);
+          done();
+        });
+      });
+    });
+  });
+});