The support groups I lead are community-based and peer-led. Community-based means that they happen in the community, the neighborhood where we live, instead of at a non-profit or social services agency. Peer-led means that the group organizer identifies as someone who shares a common experience with other attendees. An example of another community-based peer support group is an AA (NA, Al-Anon, etc.) meeting.
For almost two years, I led groups as an "expert", not as a peer survivor, at a non-profit agency. These were psycho-educational groups where attendees were screened for mental health challenges (and more) before they were allowed to attend. As the leader (and a paid staff person at this agency), I was actively discouraged about being honest about my own history as a survivor.
So, I've seen both sides.
And there's a BIG difference.