HR to delegate access to Talent Review to line managers

Hello,

Our customer needs to give HR the role of Business Leaders in Talent Review and let them designate the line managers responsible for preparing the review content.

How can we enable HR to delegate access to some line managers?

Clarification : we want the HR to delegate access to the Line Managers instead of designating them as Reviewers because the customer doesn't want the Line Managers to access the Talent Review Meeting (dashboard), but only to prepare the review content.

How can we meet these two requirements?

Thank you for your feedback,
Lise