Sub-Forum levels I want 3 levels of forums

[Ultimate Killer]

How do I go about getting to a third level of sub-forums? I've tried the forum display section but no matter what numbers I added, the forums still looks the same.

Basically, what I would like to have is this.

Home page category/subforum/
level 2 subforum
level 3 subforum

Right now the level two subforum is working fine but the level three subforums are lined up underneath the level two subforum instead inside the level two forum.

Can someone please help me with this, it's driving me nuts.

Thanks in advance.