How can a user edit a record during Approval Process even if they are not assigned as Approver?

Hi Saurabh,

Users with the following permissions can respond to approval requests, even if they aren’t designated approvers.
“Modify All Data”
“Modify All” for an object
Make sure that the assigned approver has access to read the records for the approval requests. For example, a user who can’t view expense records can’t view expense approval requests.
Approval processes that let users select an approver manually also let users select themselves as the approver.
You can assign an approval request to the same user multiple times in a single step. However, Salesforce sends the user only one request.
Here’s what happens to the list of approvers after a record enters an approval step and the approval process later returns to that step.
If the user who responded isn’t in the designated approvers list and has either “Modify All Data” or “Modify All” permissions for the object, that user replaces the original approver in the list of approvers.
If a user who responded is in the designated approvers list, the list of approvers for that step don’t change. This behavior occurs even if the field values that designate the approvers have changed.