On a team's page we can see all teams that team is a member of (under the "Subteam of" section). How about a link (shown only to team admins) beside each team name which takes the user to the page in which it's possible to cancel the subscription? I'm also accepting suggestions for the link's text, as 'Leave' may not convey the right thing (the team, rather than the user, is leaving the other team).
On a team's page we can see all teams that team is a member of (under the "Subteam of" section). How about a link (shown only to team admins) beside each team name which takes the user to the page in which it's possible to cancel the subscription? I'm also accepting suggestions for the link's text, as 'Leave' may not convey the right thing (the team, rather than the user, is leaving the other team).