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:
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Add the users you want to share with (or create them), and click Send Share when you're ready.
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I hope you found this helpful!