Have not tested this myself, but according to SDK:
NumberOfLevels (inherited from PageTreeData) Number of levels to show in tree.
Sounds like a promising candidate.
Still won't get the 3 levels to work even with NumberOfLevels!?
The menu should look like this
menyval:1-1 <- nivå 1
menyval:1-1
menyval:1-2
menyval:2-1 <- nivå 2
menyval:2-2
menyval:3-1 <- nivå 3
menyval:3-2
menyval:3-3
menyval:2-3
menyval:2-4
menyval:2-5 <- nivå 2
menyval:1-3
menyval:1-4
menyval:1-5
menyval:1-6 <- nivå 1
any 1 got code examples for me?