The Approver View Access allows an Approver to view other Approver's pending approvals as well as previously approved or denied requests.
It does not, however, permit an approver to approve/deny another approver's pending approvals.
Steps:
You must be a Superuser or have custom permission to access Approver View Access.
Navigate to Settings → Approver View Access.
On the left, select the applicable Approver to grant viewing access
Click Manage List.
On the right, Select Approvers whose approvals should be visible to the Approver selected on the left.
Click Save.
When enabled, the approver will have a drop-down at the top of their approval module.
Use this drop-down field see the approvals of another Approver. The "All" option will only display the approvals of the approvers granted as per the steps above.