Quick Fix to view request feedback functionality in CPM
Reproducing the problem
Request feedback does not show in Continuous Performance management
Solution: Go to RBP > Continuous Performance User Permissions.
Make sure ‘Limit about whom feedback can be requested’ is checked.
Please review the following article to know how to set feedback in CPM https://blogs.sap.com/2018/05/03/quick-steps-to-enable-feedback-in-continuous-performance-mangament/