Your direct report's performance rating is not shared with anyone, not even your direct report(s).
This performance rating will help you keep track of your direct report's performance and discuss it, during your 1-on-1 meeting, if any concern arises.
No one from your team, department, or organization can view the performance rating you give to your direct reports.
To check-in to your direct report's performance open their 1-on-1 meeting and rate their performance on the popup that comes up. You can also select the reason for their high or low performance to review it later, any time you want.