How to allow a next level manager to add notes to a check-in document?

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Is there a way that a workers' managers' manager can add a note to a check-in document? 

This will be necessary if the manager is on a leave or if the managers' manager is more engaged in a specific check-in topic. 

In our test environment, as the managers' manager, I can see, but not add notes to my direct reports' workers' check-in documents. 

If the above is not possible, how could a check-in document be transferred to another manager in the event of leaves to ensure continuity of the check-ins for the worker?