New Legal Entity how to separate roles

Summary:

Hi,

Our company has split and therefore we have now 2 legal entities. How do we separate the roles?

Content (required):

Is duplication the only way of separating the roles. As we like employees in the respective legal entity to only access their data.

Also we have audit from time to time so we need to show that the data is secured properly.

Would a one to one relationship of data role to security profile be best?

We would like to as minimum work as possible as duplication would mean creating duplicate roles, security profiles, approval rules etc.

Version (include the version you are using, if applicable):