Go to Onboarding > Account > Settings. Scroll down to Employee Custom Fields. Select Add Employee Custom Field.
In the pop-up, select the field type (similar options as prescreen questions) and create a field name, mark the field as required or not, and designate whether it can be prefilled from the employee record. Another option is whether the field is visible on the Personal Info page for the employee to edit on their own (i.e t-shirt size or emergency contact) or the Management page so that only the manager can edit it (i.e. employment or pay type). Click Save when you are finished editing the field.
If you want to edit your custom hiring fields, you can use the arrows on the left to arrange the order in which they will appear on your employee report. You can also edit the field itself by clicking on the pencil icon or delete the field by clicking the X.
When you are finished editing your custom fields, they will be available for selecting when editing your employee report.