I feel so much nostalgia for the usernames I am reading in this old topic.. all people I used to engage with back in the day when Discourse was still new. 
@moin that’s true - the OP here is about the “User” filter which has existed for a while now, to see all flagged items for a particular user.
Sam has now added a new “Flagged by” filter which finally lets us see all items flagged by a particular user. We’ve never had that before but it will be very useful!
We also have a “Reviewd by” filter which would be the moderator who handled the flag.
Should we rename the “User” filter to “Flagged user” to distinguish between them better?
I remember these circles! I guess they were removed at some point because of the noise they created on user profiles. But having some way to get to the “User” and “Flagged by” filter would be helpful.