At MapR, we chose a top level filter pattern. Customers approve. In fact, nary a complaint nor bug is filed from anyone using the product to analyze and administer their large scale compute clusters.
Function: The pattern allows people to add/remove filters at will. Moreover, the options within the filter pivot on the Expression Subject... In other words, when you select anything in the first expression subject, the expression operator updates, and the expression value input updates.
Persistence: So you filtered some data... cool. How can you share this state with others, or better yet, bookmark it for later? Use the url hash to your advantage. This doesn't need to be completely human readable, but simplistic, and extensible to multiple patterns of filtering. See the url in the image below for reference.
I apologize because this site will not allow me to post the screenshots I have illustrating this example in detail because I am a new user here and need 10 points reputation... when I get the 10 points, I promise to return and update this post.
Update: 10 points gotten. Images uploaded.
Good luck to you.