Your library's Security Administrator defines Reviews Roles in Author by using the Folder Action Permissions screen. The roles require a minimum of List Object and Read Object permissions.
Only users assigned to the Author or Reviewer role can log in to Reviews, with the exception of the Security Administrator role, which sees all Reviews.
Permissions for folders
Permission for Read Objects only enables users to see a Review; they cannot expand the book contents while the review is in progress.
Permission for List Objects enables a user to see a Review and expand the book contents. If you are initiating a Review, you must have a minimum of List Objects permission so that you can view a book in the Review form's Book List.
See your Security Administrator to Assign folder permissions for Reviews.
Reviews uses permissions to maintain security integrity
If a reviewer does not have read permission to a folder, the reviewer is unable to review content in that folder. This is so Reviews does not compromise an organization’s security strategy.
If a reviewer is assigned to review a book and that book has specific topics to which the reviewer has no permission, those topics are not visible to the reviewer in the Reviews Table Of Contents.
Reviewers also require permission to any release states used in a review, and reviewers without appropriate permissions do not see those topics in the Reviews Table Of Contents.
See Effect of permissions on viewable content for examples of both folder and release state permissions that affect a review.