title: Azure DevOps: Query work items by state of related items
body: <p>I've recently been playing around with the Predecessor/Successor relationship between user stories within a feature; an example would be, I have to complete the "The widget list needs to be grouped into a tree-view by location" before I can work on "Add my cool new widget into the 'Manager Office' location node". It makes for a nice little tree of items where, when someone wants to start working on a story, they have a direct link to make sure there's nothing else that needs to be finished first. However, I can't seem to find a way to query stories based on the state of that related item.</p>
  
  <p>Basically, I want to say, "Show me all user stories that are not resolved and either have no predecessors or all of their predecessors are resolved." I'm working from the Queries tab under Boards, and the only query option I see that's even vaguely related is the "Related Link Count". I'm not entirely sure that what I want to do is possible via the web interface.</p>