Collapse Level 2 sub-categorys?

[Rocko]

I searched now a few hours but haven't found any results/solutions for this.

I am able to collapse Level 1 Categorys (which collapse the level 2 forums).
But I am not able to collapse Level 2 Categorys (which collapse the level 3 forums on the Forum Home Site(I copied the level 3 templates from the level2 templates))

Is there any way to collapse the Level 2 categorys as well?