Access to lead and customer records can be granted temporarily to a user. With work stacks, you can do this in bulk.
For more information on delegation in general, read this article.
This is permissions based, if you don't have this ability, please contact your Layer administrator.
In our example we have used a lead stack, however the process is the same for customer workstacks.
With your lead stack open, check the box for each of the records for which you want to grant access. You may want to filter on the various headers to help you find the records you want.
Click Delegate and confirm when prompted.
Select the user and expiry for the access. The default delegation period is defined in your company settings - please check this article for details.
Confirm, and delegation is complete.