Hello
 
I have just seen this example on a store
 
Sorting the products by Sub-Categories
 
Check here
 
http://www.asos.com/Men/Sale/Polo-Shirts/Cat/pgecategory.aspx?cid=5229#state=Rf-200%3D3&parentID=Rf-300&pge=0&pgeSize=20&sort=-1
 
 
Its really intuitive and uses javascript to update the page.
 
 
What do you guys think ?