title: Magento: Showing sibling categories in layered navigation
body: <p>I would like to add sibling categories to layered navigation (whenever a customer is is 
  already one layer in).</p>
  
  <p>In other words: lets say I have a category called 'Animals' and sub categories named 'Cats' 'Dogs' and 'Lions' respectively, if a customer clicks on 'Lions' I want them to see in "Shop by category" Cats and Dogs.</p>
  
  <p>Does anyone have any idea on how to do this?</p>
  
  <p>Thanks in advance.</p>