If your organization plans to assign a particular interview to the same users for the duration of a job search, you can configure those users as a default interviewer so they are automatically added as interviewers when a candidate interview is scheduled.
Click All Jobs from your navigation bar and select a job from the list.
Click Job Setup on the left panel.
Select Interview Plan.
Find the interview you want to modify, and click the Edit icon.
Scroll down to the Interviewers panel and select users from the Set default interviewers dropdown field.
When you're finished, click Save.
Now, when scheduling this particular interview, the Interviewers field will automatically be filled with the assigned users.