title: xslt grouping flat content to multiple listing
body: <p>I have searched for the following problem, but I can't find the right solution.</p>
  
  <p>I have flat listing:  </p>
  
  <pre><code>&lt;list&gt;
  &lt;p class="1"&gt;1. Voice of the Customer/Business/Process /Employee&lt;/p&gt;
  &lt;p class="1"&gt;2. Value add trefwoord 4:&lt;/p&gt;
  &lt;p class="2"&gt;a. Waste&lt;/p&gt;
  &lt;p class="2"&gt;b. Process flow:&lt;/p&gt;
  &lt;p class="3"&gt;- Process flow&lt;/p&gt;
  &lt;p class="1"&gt;3. SIPOC&lt;/p&gt;
  &lt;p class="1"&gt;4. Takt time&lt;/p&gt;
  &lt;/list&gt;
  </code></pre>
  
  <p>I want to transform this xml in a multiple list with hierarchy like this:</p>
  
  <pre><code>&lt;list&gt;
  &lt;listitem&gt;&lt;p class="1"&gt;1. Voice of the Customer/Business/Process /Employee&lt;/p&gt;&lt;/listitem&gt;
  &lt;listitem&gt;&lt;p class="1"&gt;2. Value add trefwoord 4:&lt;/p&gt;
  &lt;list&gt;
  &lt;listitem&gt;&lt;p class="2"&gt;a. Waste&lt;/p&gt;&lt;/listitem&gt;
  &lt;listitem&gt;&lt;p class="2"&gt;b. Process flow:&lt;/p&gt;
  &lt;list&gt; 
  &lt;listitem&gt;&lt;p class="3"&gt;- Process flow&lt;/p&gt;&lt;/listitem&gt;
  &lt;/list&gt; 
  &lt;/listitem&gt;
  &lt;/list&gt;
  &lt;/listitem&gt; 
  &lt;listitem&gt;&lt;p class="1"&gt;3. SIPOC&lt;/p&gt;&lt;/listitem&gt;
  &lt;listitem&gt;&lt;p class="1"&gt;4. Takt time&lt;/p&gt;&lt;/listitem&gt;
  &lt;/list&gt;
  </code></pre>
  
  <p>I tried with several grouping code but I don't get it right. Could someone help me please. Is there a way to do this?</p>