Access to Performance Document during Approval stage (Link to document is not active)

Summary:

Content (required):

We have a following case from our Customer:

Performance document should be approved by Head of Department, HRD, Finance Specialist.

When HRD receives notification for approval she can see the buttons Approve and Reject but she cannot open the Performance Document to see any details (it is greyed).

What can we do to give her access to this document?

Version (include the version you are using, if applicable):

21D

Code Snippet (add any code snippets that support your topic, if applicable):