Select Admin > Security > Data Access Role and navigate to the Access Groups tab to define the access groups whose accounts (or other objects) may be accessed by the users in this data access role.

Use the Access Group collection to define the access groups whose objects can be accessed by this role's users. Keep in mind that when you add an Access Group to a Data Access Role, you are granting all users who belong to this role access to all of the accounts (or other objects) linked to the access groups.