title: Prism - composite view with single view model spanning on two regions
body: <p>I've search over SO but it seems I can't find anything no this.</p>
  
  <p>I have a thing like this:</p>
  
  <p><a href="https://i.stack.imgur.com/JdT0U.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/JdT0U.png" alt="enter image description here"></a></p>
  
  <p>Where view A is a list of files, and view B navigates to a different folder (breadcrumb control). View B also features some functionality if view A has some items selected (like select all, delete) etc. So basically they are related and should be one view.</p>
  
  <p>What I need is:</p>
  
  <ul>
  <li>either having one view span over two regions</li>
  <li>or having two views, but with one view model</li>
  <li>having navigation work, so if view A is navigated, view B is navigated too</li>
  </ul>
  
  <p>I'm going to have more such situations over the whole app, so I'm looking for some common infrastructure for this to work. Is that possible in Prism?</p>