Gathering user information by using IMGroups

I want to use restricted IMGroups to restrict users inside my account. In this way they are only visible for the people inside that group. I then want to make a custom application for the user. I need information about what group they are in, as well as all the members in the group. Then I want to display that information in an appropriate way. I have not found an API call that fetches user information about which group a user is in. Does anyone have a good suggestion on how to solve this problem? Is this not supported? I am also a bit confused whether to use a user managed app or an account managed app (I am using OAuth). Any suggestions on this?

Which App Type?
Using OAuth to make API calls.

Which Endpoint/s?
IM groups / groups

Hey @erikttv,

Have you seen our List Group Members API?