Thanks for your answer Ray, but this is not what I mean. I'm looking for the best way to organize within the contacts app. We have a customer which is a hospital with a VAT-number. Within this hospital, there is a lab which is a customer, with its own contact persons. But there is also a pharmacy in this hospital, which is still a sales lead for us, with its own decision makers. 

Divisions are what Odoo calls Branches.

See https://www.odoo.com/documentation/18.0/applications/general/companies.html#branches