Office 365 synchronisation


I have set up a synchronisation project with a test O365 tenant using Azure connector.

The provisionning is working fine.

Now i have a main domain xxxx and i added a  subdomain yyy to O365 and i can see them  in one identity Manager.

I have two populations and i want to automate provisioning O365 by affecting domain xxx to population xxx and domain yyy to population yyy

How can achieve this ? i can't attach a domain to a Business role..

Should i have two O365 tenant for this ?

Thank you