Done! The issue is #4156 with the title "Feature Request: Support Multi-Organization Tenancy for a Single User" .
I appreciate if you consider to implement it to allow this new behavior in Casdoor.
There is a requirement: a hospital A uses the services of a doctor. Hospital B also uses de services of the same doctor. The doctor can work for hospital A or B. Hospital A can send a invitation link to doctor to be part of it and Hospital B can do the same.
In Casdoor, the doctor can be part of a common Organization (Org Common), the Hospital A can be other organization (Org Hosp A) and Hospital B another organization (Org Hosp B).

