Based on your roles provisioned, you have access to certain roles.
Secured access to Narrative Reporting is established by the roles that you have been provisioned within Oracle Cloud User Management Console, and access permissions that have been granted to you from within the service. Because the functionality is restricted to only the users who can perform a task, security is enforced. For example, look at the Home Page. A service administrator has access to all the functionality available within the service, but a reviewer only sees some of these tasks. If your roles and access grants are more restrictive, then you will only see a subset of the functionality.