The Financial Services Cloud capability that provides the ability to accommodate the request of sharing specific records with certain users who are not typically engaged in that account is Compliant Data Sharing.
Compliant Data Sharing is a feature that allows users to share records withother users based on criteria such as record type or field value. Users can create sharing rules for objects such as account, contact, individual, financial account role, opportunity participant role, or case team role. By using Compliant Data Sharing, the financial institution can share records with legal and compliance members who must be engaged for particular deals based on a field value that indicates the deal type.