How to sync users from a second domain using AD Connect
Do you need to integrate a new company in with your existing employer and therefore in to your already provisioned Azure AD tenant. Or perhaps just need to share your tenancy and office 365 services with more than one company, then you could find yourself in a position where you need to sync users from another domain and have already configured AD Connect, well there is a way to add the second domain to your current Azure tenancy, so you can sync those users from the second domain.