Hi David! Unfortunately DataHub lacks a first-class entity model that directly models the concept of a service, as up to this point the main focus has been on modeling the primitive "asset" types of a data ecosystem - tables, dashboards, data pipelines, etc.
That being said, if you really want to model this, I'd suggest ingesting these services as "DataJobs" and "DataFlows", which are semantically the closest thing to what you're looking for. These entity types are supposed to model the processes that read, transform, and produce derived data.
If you emit aspects for each of these entity types, such as the dataJobInputOutput aspect, you'll begin to see them appear in the lineage view relating tables to one another.