Reference fields require additional roles. Reference fields have a magnifying glass next to them, linking to other tables. To view a reference field, a user needs table read and field read access to the field. For example, to see a user record and the title field on the user record, the user needs roles that give read access to the user table and the title table. Then, at the field level, they need access to the title's name, which is displayed in the reference field, and the user title field.

Reference fields are useful becuase they allow you to make changes to the underlying record and that change will be reflected in all the places where the reference field is used.