title: WordPress - list multi-level parent pages when on a 3rd level child page
body: <p>I'm working on a website at the moment, and the navigation works as follows (by client specification).</p>
  
  <p>Underneath the header there is a horizontal navigation listing the top level pages, clicking on one of these takes you to page.php, which has a vertical navigation in the sidebar listing the sub-pages of that particular page like this:</p>
  
  <p>2nd level
  - 3rd level
  - 3rd level
  - 3rd level
  2nd level
  - 3rd level
  - 3rd level
  - 3rd level</p>
  
  <p>and so on, and so on.</p>
  
  <p>This is the code I am currently using in the vertical navigation:</p>
  
  <pre><code>$children = wp_list_pages('title_li=&amp;child_of='.$post-&gt;ID.'&amp;echo=0');
  if ($children)
  {
      &lt;ul&gt;
          echo $children;
      &lt;/ul&gt;
  }
  </code></pre>
  
  <p>What I would like to be able to do is continue to have the same vertical navigation, regardless of the current page level. I'm finding it hard to list the sub-pages of a 1st level page when you're on a 3rd level page.</p>
  
  <p>Any suggestions greatly appreciated.</p>