Nothing held back is an amazing community where experienced marketers openly share what is working well in their business right now. You can literally search the group regarding a specific topic in your business and you would find golden nuggets about it.
Now the goal of joining groups is NOT to pitch and make offers within the group. If you do, you would be kicked out. Always lead with value first.
If you have not read about the 5 Golden Rules to Facebook Organic Marketing, check it out HERE