It is quite common that a customer wants to open an incident that in fact is already opened or maybe he had they same issue in the past. In this case it can be helpful to see in the "Related items" panel the existent incidents for the customer. This article describes how to configure it.
Please follow these steps:
1.- In the form IncidentDetails.ServiceDesk, add the field "Customer Name".
2.- Change the "Control Type" to "Object Matching Control"
3.- In this case we do not want to show the field, so change the "Visible Expression" to $(false).
As you can see, the search works even when the field is not visible
4.- Save and test it.