Project Expenditure Batch Approval notification should be sent to Supervisor

Summary:

Project Expenditure batch should be approved automatically but notification should be sent to user's supervisor

Content (required):

Project Expenditure batch is getting approved automatically when user clicks on Submit button and the user is getting the notification that the batch is approved.

There is a requirement to send notification to user's supervisor that the expenditure batch is approved. ProjectExpenditureBatchApprovalNotifyTask works with Approval Group however it doesn't work with supervisory rules.

Additional note: The notification works if I use Approval Group but the requirement is to use supervisor hierarchy.

How to send notification to user's supervisor?

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