Is this a self moderated group?

For some people, groups are their only outlet. For some, groups are the closest thing to being social that they have. Thus the tendency to rehash and talk about their problems ad nauseum. This is where a good moderator is essential. A good moderator would also allow (you) everyone to share and give them the sense it is safe to do so.

Moderating is a skill. A good one will use a combination of open and close ended questions to steer the discussion for example, from repetitive discussion to different topics in order to allow for as much and wide a talk as possible.