Techdows recently tipped and reported that for the first time, Firefox allows the shortcut key Ctrl+Shift+B to hide the bookmark toolbar on Windows. In order to make it easier to access bookmarks saved to “Other bookmark folders”, starting from Firefox 84, the bookmark toolbar will display other bookmark folders. If you move the bookmark to another folder or bookmark menu, the folder will be automatically deleted from the toolbar.
Things you need to know about hiding Firefox Bookmark button:
Other bookmark buttons will appear in the bookmark toolbar;
If you don’t like this feature, Firefox provides a hidden option.
Hide other bookmark folders on the bookmark toolbar in Firefox
1. Load about:config in the address bar;
2. Make sure Boolean Pref is named browser.toolbars.bookmarks.showOtherBookmarks. If you did not create it yourself;
3. You can set its value to “false”, or right-click the bookmark toolbar and uncheck “Show Other bookmarks”. It is worth noting that at the time of writing this article by techdows, UI options or hidden pref controls the visibility of other bookmark buttons are not available in Firefox 84, but exist in Firefox 85. So when Mozilla releases Firefox 84, this option may or may not be available.