To organize your bookmarks:
Click the open-book icon.
In the bookmark list that appears, the left column shows collections like News and Sports, represented by folders. Bookmarks Bar and Bookmarks Menu are collections, too, and can be organized like regular collections.
Choose how you want to organize your bookmarks:
View a collection: To see the contents of a collection, click the collection’s name.
Create a collection: To create a new collection, click the Add (+) button at the bottom of the left column. Replace the name “untitled folder” with a name of your choosing.
Add a subfolder: To add a subfolder to a collection, select the collection and click the Add (+) button at the bottom of the right column. You can also nest folders by dragging one folder into another.
Move and copy bookmarks: To move bookmarks from one collection to another, select the collection that currently has the bookmark, and drag the bookmark to the new collection. If you want the bookmark to be in both collections, hold down the Option key as you drag.
Reorder collections: To change the order of collections, subfolders, or bookmarks, drag them up and down. You can’t change the position of the Bookmarks Bar or Bookmarks Menu collections, which are always at the top.