How to accomodate employee grievance in the performance ratings?

Summary:

When the final ratings are shared by the HR admin with the employee, how can the employee reject the ratings given to him?

Currently, when the final ratings are shared with the employee, the employee can acknowledge the ratings but there is no option for the employee to reject his ratings provided. How can the employee show his grievance towards the ratings provided?

Content (required):

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

Code Snippet (add any code snippets that support your topic, if applicable):