Change service providers based on Multisite in appointments+

I will be breaking the site up into Multisite (locationname[city].XXXXX.com) and I am wondering how I would go about configuring Appointments+ to differentiate which service providers would be available in each domain.
As an example:
toronto.XXXXX.com - lists only toronto based service providers
calgary.XXXXX.com - lists only calgary based service providers

I am looking forward to your detailed response.