title: Getting users under roles within governor limits
body: <p>I have a hierarchy of roles and its subroles in a map.
  I want to fetch all users under each role and have all the users under that user.</p>
  
  <p>For example </p>
  
  <p>Role : director Marketing</p>
  
  <p>SubRole : RM East</p>
  
  <p>SubRole : RM West</p>
  
  <p>Subrole : RM North</p>
  
  <p>Subrole : RM South</p>
  
  <p>i have this as   <code>Map&lt;id, set&lt;id&gt;&gt;</code></p>
  
  <p>If Phil is the Director Marketing
  i want all the users reporting to Phil and under those users also have users reporting to RM. There could be multiple users under each role i would need help to find a way to capture these in some collection.</p>
  
  <pre><code>Phil - Director Marketing
        Kevin - RM South   
             Clara - TM
             Joe   - TM
        Robin - RM North
             Rita  - TM
             John  - TM
  </code></pre>
  
  <p>I am not sure how to go about doing this.</p>
  
  <p>Thanks</p>