How to send reminders of pending approvals to all stakeholders in the transaction

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Hi,

Client requirement is to send the reminder notification not only to approver but also to other person such as creator, other approvers in hierarchy etc.

When a requisition is created, it is assigned to an approver. If certain time elpase, then requester, approvers (the one to whom task is assgined), other approvers (either who have already approved or who are yet to be approved in further chain of hierarchy), buyers should receive notification as well.

I can see in BPM we have feature to enable reminders but it is only to approvers who has been assigned the task of approver.