SQL Trackcare, accessing linked table data

Hi Experts

I am trying to pull the code tables Information and this code table has linked  code table not exactly obviously joined by SQL tables or columns. This is confusing me. Please can you clarify how to link these two tables. 

I will be generic to ensure, any privacy is protected

CT_Hospital has CT_Staff linked in.

When CT_Hospital has data, for that relevant hospital code, CT_Staff can be clicked and data entered. 

When I see in the Components - > Items I do not see any SQL table or SQL column common between CT_Hospital and CT_Staff. 

Question: How can I join CT_Hospital with CT_Staff. The layout and component of CT_Staff as Parent reference with websys.parent but not as SQL table / Column. 

Your help would be appreciated and Please kindly request you to write in detail as I new to the system.