With a hiring manager:Go to the Design tab, and scroll down to Internal Hiring Team. Here you can add users to be a part of the team, and this will allow them to view candidates.
With a collaborator/someone not on the hiring team:
In the candidates tab, select the candidates you wish to share, then click the share button:
Add the users you want to share with (or create them), and click Send Share when you're ready.
I hope you found this helpful!