Hi Komal,
you need to keep separate status for approval .
like - Approval 1 - Status 1 (Pending , Approved)
Approval 2 - Status 2 (Pending , Approved)
Approval 3 - Status 3 (Pending , Approved)
also manage final status at final approval.
If approval 1 pending or approved at same time approval 2 can see . once approval 2 can approved then
goes to Final approval.
Hope it will help you.
Regads
Rahul