The Multi-entity feature of Zuora Billing allows you to have multiple entities within a single Zuora tenant.

If you want to use Quote Studio and have multiple Zuora entities connected to one Salesforce org, you must enable the Billing Entities tab. Once it is complete, you can find that all available entities are listed in this tab. Then you must designate one of the entities as the default entity so that Quote Studio can filter the relevant product catalog.