MyBB Community Forums

How do I make an entire category invisible to certain usergroups?

I recently moved back to MyBB, and I know this used to be possible. I have tried everything, and all I can do is make threads, and posts invisible, not the category or forums within it.

see http://docs.mybb.com/Admin_CP_Forum_Mana...ermissions

Thanks, but I have all the permissions set properly, and all it did was make the threads within the forums invisible.

Another Admin on my site looked, and said it is set right, and then I told him to go look at the forum as a guest.