Changing the menu active-trail depth
The Menu Trail By Path module will accomplish this:


  Menu Trail By Path sets the active-trail on menu items according to
  the current url.
  
  For example if you are at yoursite.com/blog/category1/article1
  Menu
  Items with these paths will get the active-trail class on them and
  expand accordingly.
  
  blog blog/category1 blog/category1/article1