XF 2.1 confused on group permissions

[CaptFacePwn]

So i run a milsim unit and the permissions need to be set so certain groups can see certain forums and "Civilians" can only see what is public..

i read up on it they suggest making all other groups as secondary and leaving everyone as registered.

whats the best way to go about solving this problem?

 

[Dubbed Navigator]

Registered group should be the basic for all of you members, granular from there

Create an additional usergroup for the area you wish to be private. In that forum, click permissions, mark it as private and underneath that allow your new usergroup to see it. No other usergroup will be able to see it unless you do the same for them.