How to build a query which returns the parent's ref_num.
The main goal is to have a condition to use on “Additional Search Argument” which returns all parent tickets (so that these parent ticket must have children tickets associated).
Release : 17.x (17.1 / 17.2 / 17.3)
Component : CA SERVICE MANAGEMENT
The way the architecture is defined on the parent-child relationship on CR object is limited.
Deal with Qrel relationship related queries, spel code would be need for achieving any of such requirements.
In short, the requirement is not possible directly using the web interface environment.
Below is the document which might help you understand the object layer defined around the CR Object and its defined table fields.