title: Remove a directory from a URL with regex
body: <p>I have a site with the following URL structure in places:</p>
  
  <pre><code>www.sitename.com/folder/sub_folder/item
  </code></pre>
  
  <p>What I need to do is remove the <code>sub_folder</code> part so that it displays as:</p>
  
  <pre><code>www.sitename.com/folder/item
  </code></pre>
  
  <p>Is there a regex expression for that?</p>