You can report on additional fields created in Recruiting Setup > Job Requisition Additional Fields using the following query entities under the Recruiting category in Reporting and Analytics > Reporting > Reports:
- Job Requisition Additional Fields
- Job Requisition Additional Fields Answers
- Job Requisition Additional Fields Assigned
- Job Requisition Additional Fields Data Type
- Job Requisition Additional Fields Options
- Job Requisition Additional Fields Role Security
For more information about the fields available for each of these entities, see the Reporting Reference Guide.