Hover or following link for @ mention of groups in issues/comments should link you to the people that got notified
Problem to solve
It's hard to know who was notified when mentioning a group. Even following the link now doesn't take you to the members page but even worse without https://gitlab.com/gitlab-org/gitlab-ce/issues/62568 you can't even see at all who was mentioned by going to the members page because the members list includes inherited members but not all these people are notified.
Intended users
People that are @ mentioning groups in GitLab
Further details
Proposal
Consider a hover popup which shows you the preview of the people mentioned. This obviously won't scale to a lot of people but for small groups would be really nice.
Then the scalable solution is that it should link directly to the members list that were notified which will probably require https://gitlab.com/gitlab-org/gitlab-ce/issues/62568 to be implemented first.
Permissions and Security
There may be security implications here for mentioning private groups. Presumably we can't show the hover list if the group is private and the user is not allowed to see that group members.
Documentation
Probably doesn't really require documenting...
Testing
What does success look like, and how can we measure that?
It becomes much easier for me to see who were just notified by a group mention.