You can use groups to split your discussion forums into smaller conversations. For more information on setting up groups in your course, see Create a group.
What's the difference between separate and visible groups?
In Separate Groups, students will be completely separated; they will only be able to see and post in their own group’s forum. With Visible groups, students can only post in their group forum, but they can visit and read posts in the other groups’ forums.
How do I look at the different forums?
In the forum, you will be able to change your view to All Participants, or just view one Group at a time.