Many thanks Anton, I'll explore that solution. I see that the system was developed to sell membership levels, which limits the sale of other things. It would be ideal to disassociate membership level with duration, to be able to sell several things with the same duration to the same membership level.
The thing is that I’m not really interested in selling membership levels, but for example if I want to charge a $5 monthly subscription fee to members (any membership level) for joining a Group and a member wants to join two Groups. How can he/she pay for that?
So in this case the product would be Group monthly subscription, not a Membership level.
Hello. Current version of Groups app allows to use Paid Join. Group creator/admin may add pricing options for his group and users would need to pay before join. Each group may have its own pricing options, for example, Group 1 may sell monthly subscription for $10 while Group 2 will sell monthly subscription for $5. In this situation we have different groups with the same durations and it's not the same as "to sell 1 month of a Premium membership for $10 and for $100".