Creating a sub-menu
A sub-menu (drop down menu) allows you to nest up to 15 sub-menu items under a single menu item.
A sub-menu creates a new top-level menu item under which you can then add more sub-menu items. Existing menu items can’t be used as sub-menus, so you’ll have to set up new ones.
To create a sub-menu, use the + sub-menu button at the bottom of the menu editor. Once you’ve named your sub-menu, you can proceed to add links by clicking on the Add button directly under your newly created sub-menu.
You can reorder sub-menu items just like any other menu - simply drag and drop the items into the desired order. Using separators is also possible.