Side Menu

Does anyone know how to create a side menu like the one in the Xojo IDE?

I see the same interface is also used in the Feedback app and it’s quite common to have nested menus down the left side of a window like that. Especially with Xojo’s foray into Web applications, where this type of vertical menu is very popular, I’m surprised that creating one isn’t more obvious.

its a hierarchial listbox…
my Treeview control can duplicate that functionality