Status Quo now: The dialog (pop up) cannot be modified as it is based on the duplicate detection rules that are set for the entity. These rules are automatically generated as the view for the dialog (pop up). The first column is the primary field and the last is 'Modified On'. Both cannot be removed.

It would be a benefit if a system administrator is able to customize the views in Duplicate Merge dialogue like a standard view in Dynamics 365. Therefore it should exist an extra view, to define the attributes, which should be shown in Duplicate Merge dialogue, so that the user experience gets better.

Because for now, the usage depends on the amount of duplicate detection rules, which means that the clarity is horrible once you are using lots of duplicate detection rules.