Data structure for multi-person matches

Hi there — I’m working on an app to help form small discussion groups. I’m imagining a Tinder-like functionality, which I know how to create from watching a few tutorials (matches field in the data structure, to hold multiple items,)

That works for matching Person A and B. But say I wanted to let Person A, B and C all know they matched each other, and would be good for a small group discussion.

Any ideas on how to pull that off in the database?

Thing 1: Group
Thing 2: Person
The group has a list of persons