title: How to build a group of groups with pattern in an ansible inventory?
body: <p>I want to build up a target host list of hosts which are in both groups DC-North and DC-South and which are not a DB Server.</p>
  
  <p>This was my approach which unfortunately fails: </p>
  
  <pre><code>[DC-North]
  host1
  host2 
  
  [DC-South]
  host3
  host4 
  
  [dbservers]
  host3
  host1 
  
  [target:children]
  DC-North:&amp;DC-South:!dbservers
  </code></pre>
  
  <p>How would I define this correct?</p>