Custom role creation with data restriction in HCM for one Legal Employer/Entity

Good day to you all !

We are creating a service user in HCM Fusion to do REST based operations from a third party application. Currently we have a role exists, which has all the required privileges/use REST SERVICE roles. The challenge here is to restrict, the new user to retrieve/manipulate only that data belongs to a single Legal Employer/Legal entity. Under our organization, we have multiple Legal entities available and using this third party applciation, hence this concern is raised.

Can the configuration from HCM Data Role Security Profile be used for this ?

Any kind of advise would be really appreciated.