The sections name actually means Wiki, Blogs, Forums etc. to allow an item to only appear on those sections.
If you want to create a submain you have to base it on the Order
Any items that appear under a section type will be in that submenu, this does limit you to one level of submenus and you cannot nest them.
The solution is to use the file option with phplayersmenu, I think this secret is still in the code and no documentation exists.