You may need to implement Active Roles, where split permissions are implemented:
Microsoft link: Understanding split permissions
This would entice that Active Roles would need to support two different Service Accounts:
Active Roles, currently, does not support split permissions. An enhancement request TF00090950 has been created detailing the feature above.
The product team will evaluate the request and this feature may become available on a future release of the product.
Please refer to this article for updates or contact support referencing the Enhancement Request ID: TF00090950.