We've improved the business partner integration with SAP Master Data Integration.

We've made it possible for you to copy the ID mapping for your sales organization in SAP Cloud for Customer from the SAP S/4HANA communication system to the SAP Master Data Integration communication system. This feature isn't available out-of-the-box and requires custom implementation. See this blog on SAP Community. This feature enables SAP S/4HANA sales organizations of business partner to be mapped to the SAP Cloud for Customer sales organization.