The employee can add or nominate the reviewers once the cycle is initiated.
To nominate the feedback givers on my action items page
1. Click on the nominate raters link on my action items page
2. Search the employee and add the employee.
3. After adding all the reviewers, click on confirm all reviewers
4. The feedback givers will be successfully nominated
PS: Synergita implementation for your Organization may vary from how the features are described here. The screenshots given here may also be different from what you see in your system. Please talk to the concerned person in the Organization for any specific queries.