you should make a page and add it into the menu. then a child page should be made and its attribute “Parent” refers to the previous page. for instance:
1) we create page1 in menu
2) we create page2 as a child of page1. it means that page1 is parent of page2 (you will find this in the right side {page attribute}).
3) go to the menu control and add page2 as a new item in your menu
4)click “Edit menu item” in the menu page for page1 and drag page2 into its space.
that’s it!
