title: drupal - multiple relationships for views filter
body: <p>I hope someone can point me in the right direction.</p>
  
  <p>I have a calendar view with an exposed filter.</p>
  
  <p>I have a parent node and 2 child nodes. Each of these optional child nodes have a common taxonomy term reference field called region.</p>
  
  <p>I would like a single exposed filter which will filter the region selected in either child1 or child2.</p>
  
  <p>I can get it to work for one child node or the other, but am struggling to get it to work with both in one filter. </p>