Final answer:
A client's information about multiple supported domains/hubs can be found in the domain management system or administrative portal of the hosting service or platform in use.
Step-by-step explanation:
If a client has multiple supported domains/hubs, you can usually find that information within the domain management system or administrative portal provided by the service host. For instance, in the context of a web hosting platform or a service like Microsoft's Active Directory, you would check the domain management interface or the administrative portal for a list of domains or organizational units (OUs). Typically, these portals allow administrators to view and manage the various domains and related settings. If the information is not readily visible, one may need to delve into specific configuration settings or contact technical support for assistance.