How do I move a favorite or a submenu to another submenu?

You can edit a favorite, open the Menu Options tab and select a new submenu in the Favorite parent menu list.

But a quicker way, in the Customize window, is to select the favorite (or multiple favorites with Shift + Click or Ctrl + Click) and hit the Move button or press Control + M. You can move submenus or groups as well, using the same techniques.

In the Move Favorites dialog box, select the new submenu for your favorite(s) and the position in this menu. And click the Move button.