If you are any of the Selection Stage owners you can give your evaluation using below steps:
1. Under Hiring tab click on "Submit Candidate Evaluation"
2. Candidate details will get opened
3. You can give your assessment if required by clicking on Candidate Assessment
3. You can also schedule an interview (is it is an interview stage) by clicking on Schedule Interview
4. You can view Candidate's profile by clicking on Description
5. Finally you can take your action by selecting either of the options Shortlisting the Candidate, Rejecting or putting Candidate on hold from Action drop down