add subitems for the suit menu subitems(3 level tree)

[ElsawyAhmed]

Is it Possible to structure a 3 level tree with django-suit menu?
If yes how can I do this or if there is another way to customize in the menu.
what i need is something like that:

Main Menu|
|- SubItem1
|- SubItem2 |- SubItem2-1
|- SubItem2-2
|- SubItem3