Engagement Circles/Groups for Reddit/Facebook Groups etc.

I'm seeking a way to foster structured discussions within our engagement circle that spans platforms like Reddit, Facebook groups, and more. For example, Jon could start by asking, "I'm looking for a tool that does X, Y, and Z." Then, Mark from our group might reply, "I recommend Tool A for that purpose."

Are there any services here that offer that?

never heard of such thing, but you can check for yourself in the marketplace (the misc. section):
https://www.blackhatworld.com/forums/misc.18/

If you don't find anything on the first 10-15 pages most likely there's no such service...

Would anyone be interested in joining such group? I think it can bring great value if we all came together and engaged with each others posts across various channels.