Split Navigation

I am looking for some insight! I am expanding my brand and had this idea to split my website into 2 different services, illustration service and graphic design/brand identity service. Instead of making 2 website, I want to take my current website and just make it into 2 services in one. 

My question is, I know how to make the cover page and link the 2 urls for the services, but is there a work around to have 2 different navigation menus on each URL?

Any advice on this?

Please see the following for one way it could be done.