title: how to filter a multilevel menu with a search input
body: <p>The difficulty is that the menu has many levels(like the menu in matrix-admin),and every level is large; how should i filter filter the menu on the basis of the value of the search input.</p>
  
  <p>and the output should be like this:(<a href="http://www.jqueryrain.com/?lEMFOjZ1" rel="nofollow">http://www.jqueryrain.com/?lEMFOjZ1</a>)
  and my html is like this:</p>
  
  <pre><code>&lt;ul&gt;
  &lt;li&gt;xxx&lt;/li&gt;
  &lt;li&gt;
     &lt;a&gt;xxx&lt;/a&gt;
     &lt;ul&gt;
        &lt;li&gt;
             &lt;a&gt;xxx&lt;/a&gt;
             &lt;ul&gt;
                  &lt;li&gt;
                     &lt;a&gt;xxx&lt;/a&gt;
                     &lt;ul&gt;&lt;/ul&gt;
                  &lt;/li&gt;
             &lt;/ul&gt;
        &lt;/li&gt;
        &lt;li&gt;xxxx&lt;/li&gt;
     &lt;/ul&gt;
  &lt;/li&gt;
  </code></pre>
  
  <p></p>