Bookmark Search Plus 2 (BSP2) is used to search for bookmarks and go to the Parent folder where a bookmark is stored. It is better than the "Bookmarks Manager and Viewer" (BMV) add-on in my opinion.

BMV does not search folder names for the search string, but BSP2 does.

BMV doesn't immediately display a bookmark that has been added while using BMV so I had to exit BMV and go back to the Bookmarks sidebar to confirm the new bookmark was added. BSP2 doesn't have that problem.