title: Next/Prev links for posts with same parent in wordpress
body: <p>How to create previous/next links for posts with the same parent post (not category)?</p>
  
  <p>similar to this:</p>
  
  <pre><code>$previous_post = get_adjacent_post( true, '', true);
  </code></pre>
  
  <p>but for posts with the same parent.</p>