Answer
The set of columns displayed in this kind of Multiple-Records-parameter LOV is defined at the report model level, inside the actual report definition, rather than through any separate configuration screen — it isn't something you can adjust by editing the LOV's underlying view or through a settings dialog. Changing which fields display in that specific LOV requires modifying the report itself through IFS Developer Studio, following the proper report-development process, rather than a pure configuration change; if the report containing this LOV was built as a customization, whoever built it would need to revisit the report model in Developer Studio to add the missing column to the LOV definition.