title: PowerShell select and group by nested field
body: <p>I have the following object structure:</p>
  
  <ul>
  <li>resources (Array)
  
  <ul>
  <li>resource (PSCustomObject)
  
  <ul>
  <li>Name (String)</li>
  <li>Tags (PSCustomObject)
  
  <ul>
  <li>Owner (String)</li>
  </ul></li>
  <li>more...</li>
  </ul></li>
  </ul></li>
  </ul>
  
  <p>So I can do <code>$resources[0].Tags.Owner</code> and get string value.</p>
  
  <p>The goal is to <code>select</code> just Name and Owner, and then <code>group</code> by Owner.</p>
  
  <p>I can do <code>$resources | select {$_.Tags.Owner, $_.Name}</code>, but then I get a new array of PSCustomObject with two members "$<em>.Tags.Owner" and "$</em>.Name".
  How do I do the group by the field named "$_.Tags.Owner"? </p>
  
  <ol>
  <li>Can I rename "$_.Tags.Owner" to a friendlier name and the group by it?</li>
  <li>Can I somehow tell <code>group</code> that I mean "$_.Tags.Owner" literally and not the object hierarchy?</li>
  </ol>