Thanks for your response Miriam.
We have a similar situation in that a client operates multiple business out of the same location (a roofing company and window cleaning service). Each business has a unique name and phone number. We currently have the primary business (roofing contractor) set up to "show" the address and the secondary business (window cleaning) we have chosen to hide the address and set a service area for all local directories.
I have tried to find information on best practices for this specific situation but all resources seem to focus on business with multiple locations rather than multiple business at a singular location. So, I m not sure how to best approach these situations in regards to local directories.
You'd have to imagine someone has some insight into this as "shared" office spaces are gaining in popularity.