Manage Notifications for serial approvals

Summary:

We have a scenario where there is 5 level serial approval hierarchy. And for each level we have two groups assigned, out of which one group is common among all the serial approval reasons.

As it is a serial approval, the approvals traverse all the levels to get it approved, but the common groups will get it notified for each approval reason.

Is there anyway to manage notifications so that they will receive only once. OR Is there any way where when once the common approver group approves all the approval reasons gets approved.

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