Comment 1 for bug 320076

It's a bit like the case of filed bugs vs assigned vs subscribed etc. (But the UI there is not ideal so I'm not suggesting you copy it.)

You'd also need to think here about the case of teams, where presumably they will rarely have requested reviews but it'd be interesting to see all reviews relating to their branches and/or members. (Though maybe not very interesting, if such teams are normally 1:1 with projects...)