If it’s your own Facebook Group, then you can market your programs with no problem. But if you’re in a Facebook Group run by anyone else, you’ve basically got two options:
1: Be active, provide value, answer questions and solve people’s problems to get noticed.
Because this can be time intensive, you might want to pick one group and stick with it rather than spreading your attention over several groups. Or you can outsource this work to someone else. Look for opportunities to contact people via direct messaging, to offer your free report that solves their problem, or any other opening that gets them either on your list or in direct contact with you.
2: Ask the admin for a sponsored post. This is something of a numbers game, but it can be quite effective.
Find the Facebook Groups that cater to the audience you’re looking for. Contact each Facebook Group owner or admin and ask if you can pay them to pin a post to the top of the group for a day or longer. Some of the FB Group owners will completely ignore your request, some will need more info and others will say yes. Keep in mind that unless these groups are in the make money online realm, there’s a good chance you are the first person to ask to pay them for a sponsored post.
The post itself can be an endorsement from the Group admin or it can come from you. In either case, offer something awesome in exchange for the ability to contact them via email or for joining your own Facebook Group.
Once you have them on your list or in your own Group, you can promote your products to them as you would any other prospective customer.