I recently watched Chris Coyiers talk about pseudo elements and was looking to try and do the same.
I am looking to get the effect of an arrow pointing to the content on the right
This is the location of the li that I want to target
.overviews-list > li.active > ul.submenu > li.active
You can see from the jsfiddle the style I am going for. I think the css that needs to be changed is at the top of the css.