Systems Mapping

I would like to extend the current mapping available in Promapp to include downstream relationships between the systems used in the processes captured. So a process is captured and it reference a system, but that system have a reliance on other systems to do its thing and I want to use the existing information managed in promapp to get an ultimate mapping from the front end Customer Service --> Processes we use to provide that service --> the systems used during those processes --> the back end services and systems that supports that system. The Promapp capability can give me the mapping all the way to the systems but no deeper. Is there a way to do the last step. Can I create new systems and then define relationships between those systems?