This App presents an easy way of managing groups and their memberships. It allows: -
Adding members to groups (which also lists members of the chosen group)
Deleting members from a Group
Lising groups that a user is a member of.
There are no data sources other than
Office365Groups and
Office365Users attached to the app. Note that the User needs to be a Group owner to add or delete members.
You can
download the file here.
NOTE: This Zip file is an exported (Legacy) package, not a Solution.
I hope it is useful to you.