I have spend days trying to figure it out what authentication service to use in a multiple tenant application with multiple tenant database using Azure. The web application is for the health care industry. Hospital A will be assigned an admin user, which he/she should be be able to manage(create,read,update and delete) users to log in within hospital A tenancy. Hospital B should be able to do the same, hospital C and so on. I have tried to look into Azure Active Directory B2C but I am not sure if this is a good approach since it does not seems to support multi-tenancy.
Any suggestions on what to use or how to approach this?