title: select nodes from a selection of nodes
body: <p>I've got a large XML file I'm parsing. </p>
  
  <p>My first selectNodes statement gets me a list of all elements I want to parse through. </p>
  
  <p>For each element returned by the first selectNodes statement, I want to run another selectNodes.</p>
  
  <p>The XML might look like this:</p>
  
  <pre><code>&lt;A&gt;
      &lt;B&gt;&lt;/B&gt;
      &lt;C&gt;&lt;/C&gt;
  &lt;/A&gt;
  &lt;A&gt;
      &lt;B&gt;&lt;/B&gt;
      &lt;C&gt;&lt;/C&gt;
  &lt;/A&gt;
  </code></pre>
  
  <p>I am restrained because I must parse the inner nodes, ie each subset of "A", one at a time. </p>
  
  <p>The end goal is to do something with each B,C combination, one at at time. </p>