Are you referring to Pega work parties? If yes then the way notifications to workparties work is that it identifies all the users mapped to that workparty and sends the notification automatically. It wont matter if you have a new user, as long as you map him to that work party in the initial flow, he will recieve it.
If however, your question is that the initial set of users you mapped in the initial flow are going to move out and new users may come in, then I suggest sourcing this as a dynamic list and referring it in a data transform to set up the workparty rule. As long as you remove and add the work party again just before you send out the notification, it will be current.
I think the issue you have is that there is, in my opinion, a fundamental flaw in the way work parties work.
When you create a new work party, say a Data-Party-Operator, various properties from the operator are COPIED into the work party page, which is un-necessary . You would then refer to the party as .pyWorkParty(Owner).pyFirstName etc. Obviously, if the underlying operator for the party role Owner changes then all associated other properties are out of date.
A better approach (for operator based work parties) would be to simply refer to the .pyUserIdentifier property. You will still need to update this to the new user, but you don't have to change all the other properties as you can simply access them as .pyWorkParty(Owner).pyUserIdentifier.pyFirstName
This has the added advantage that if the work party's details change, even though it's the same person, you still get all the up-to-date values
I am using CorrNew activity for sending the mail, For PartyRole Parameter I am passing "Owner" value to send mail to multiple participants at the same time.for example, For my P-1 case is having 3 owners so while sending mail all the owners are being notified.
So one of the owner get deleted from the system then I need to remove and add work party again to send mail to new owner