Invision, Phpbb3, and Punbb Categories

I see that in Phpbb2 Categories are seperated if you want them seperated, But I found a theme that is Invision or Phpbb3 and it dosent seperate what I want, It puts all the categories and forums together.
Is there a way to seperate them while using PunBB, Invision, Phpbb3, ect?

Go to your Administration Panel, click on the Display tab, scroll down to Homepage, click on Structure and hierarchy, click the option in the middle of the bottom row, and hit save.