To move bookmarks in one folder another folder, use the "Merge" function:

1. Sign in to Yahoo! Bookmarks and select the folder that contains the bookmarks you want to move. Click the Edit link next to that folder's name. The "Edit Folder" page opens.
2. At "Merge", select the folder that you would like to move the bookmarks to.
3. Click the Merge button.
4. Click Return to My Bookmarks.