Feature Request Summary:
There should be a way for Views to exclude/include Closed tickets based on whether a Follow-Up ticket has been created or not.

Description/Use Case:
In the past, when a customer contacted us to ask if we could restore their farm (this is for a computer game) our answer was "no - we cannot restore your farm."
Recently, circumstances changed, and our answer to their question became "yes - we will be happy to restore your farm."

We now want to contact all of the customers that previously received "no" as an answer and let them know that we're able to help.
To do this, we have created a View that shows all past tickets where a customer asked for their farm restored. This view includes roughly 250 Closed tickets.
Our agents are going through the tickets in this view, one by one, and contacting all of the customers that received "no" to let them know we're now able to say "yes" (as well as performing the actual restoration of the farm).

Unfortunately, our agents have no way of knowing whether a customer's case has been handled or not, without opening up the Closed ticket and checking manually for each case whether a new ticket has been created by us and the farm restored.

If we could filter the View to not included Closed tickets that have had Follow-up tickets created, this would speed up the process significantly, as our agents wouldn't have to manually click through tickets until they find one that's not been processed.

Business impact of limitation or missing feature:
Significant.