Chrome typically remembers the you used. If you accidentally saved a link to "Mobile Bookmarks" or a deep subfolder, Chrome will keep suggesting that "location" for every new bookmark. To fix this, click the Star icon in the address bar. In the popup, manually click the Folder dropdown . Select Choose another folder .
Chrome usually saves a backup in User Data\Default named Bookmarks.bak (Windows) or Bookmarks.bak-xxx (Mac). Restore it using the method in problem #1. bookmark location chrome fix
If you need to find the actual file on your computer (for backup or if Chrome won't open), it is stored here: Chrome typically remembers the you used