When filling in the form, if you can only fill in one, fill in the undergraduate course; If the recruiter asks you, you can directly answer: I have two academic qualifications (majors), full-time junior college in XX school, and major in XX; XX school self-taught undergraduate course is XX major.

If you have a resume or something, it will be more beneficial for you to fill in both. There are both full-time and self-study exams, which have certain advantages!