In Identity Manager, a user can be assigned one or more roles, or no role. With the introduction of role types in Identity Manager 8.0, it is recommended that you only directly assign Business Roles to users. In fact, by default, you cannot directly assign any of the other role types to users unless your organization had a pre-8.0 version of Identity Manager installed and upgraded to at least version 8.0. This default restriction can be changed by modifying the role configuration object (Configuring Role Types).
To reduce complexity, Business Roles cannot be nested. In other words, one Business Role cannot contain another Business Role. In addition, Business Roles cannot directly contain resources and resource groups. Instead, resources and resource groups should be assigned to either an IT Role or an Application, which can then be assigned to one or more Business Roles.