Q:

Azure DevOps: Restrict pull requests to subset of team

Suppose I have a team with 10 developers, but I want all pull requests to be completed by a senior developer of which I have 2 on my team. In my branch policy I can automatically add teams, individual users, and groups as reviewers. 
Teams - As mentioned I don't want the whole team to be able to approve the review. 
Individuals - I don't want to add individual senior devs to the policy because if those 
Sr Devs change role, move to a different team, etc I have to go update all the policies.
Groups - Would be ideal, but there's a caveat. Pull requests assigned to groups don't 
show as assigned to the user when reviewing "My pull requests". PRs only show if assigned
to an individual or a team.
Broken? Working as designed? Future functionality?

A:

The way I've managed this in the past is to have two teams:
Developers:

Matt
Mark
Bill
[project]\Senior Developers

Senior Developers:

Sue
Pam

Most privileges you define on Developers.  Additional privileges like PR permsissions you assign to Senior Developers.
One could also add the Senior Developers team as "required" on the branch policy, and keep the Developers team rights to pull requests, allowing other devs to still approve requests and comment etc. but the request can't be completed until a senior dev approves it.

