Rename to MainDashboardButton

packages/edit-site/src/components/header/index.js

@@ -15,7 +15,7 @@ import { PinnedItems } from '@wordpress/interface';
  * Internal dependencies
  */
 import { useEditorContext } from '../editor';
-import __experimentalSiteEditorCloseArea from './close-area';
+import MainDashboardButton from './main-dashboard-button';
 import MoreMenu from './more-menu';
 import TemplateSwitcher from '../template-switcher';
 import SaveButton from '../save-button';
@@ -62,7 +62,7 @@ export default function Header( { openEntitiesSavedStates } ) {
 
 	return (
 		<div className="edit-site-header">
-			<__experimentalSiteEditorCloseArea.Slot />
+			<MainDashboardButton.Slot />
 			<div className="edit-site-header__toolbar">
 				<Inserter
 					position="bottom right"

packages/edit-site/src/components/header/main-dashboard-button/index.js

@@ -0,0 +1,33 @@
+/**
+ * External dependencies
+ */
+import { isEmpty } from 'lodash';
+
+/**
+ * WordPress dependencies
+ */
+import { createSlotFill } from '@wordpress/components';
+
+/**
+ * Internal dependencies
+ */
+import FullscreenModeClose from '../fullscreen-mode-close';
+
+const { Fill: MainDashboardButton, Slot } = createSlotFill(
+	'SiteEditorMainDashboardButton'
+);
+
+MainDashboardButton.Slot = () => (
+	<Slot>
+		{ ( fills ) => {
+			// Return default Close button if no fills are provided, otherwise replace it with available fills.
+			if ( isEmpty( fills ) ) {
+				return <FullscreenModeClose />;
+			}
+
+			return <> { fills } </>;
+		} }
+	</Slot>
+);
+
+export default MainDashboardButton;

packages/edit-site/src/index.js

@@ -28,3 +28,5 @@ export function initialize( id, settings ) {
 	}
 	render( <Editor settings={ settings } />, document.getElementById( id ) );
 }
+
+export { default as MainDashboardButton } from './components/header/main-dashboard-button';