All sounds rather ambitious. Good luck.
I can only advise for roles in the UK. If you want information for the respective roles in Pakistan, you would need to ask the people in similar roles there.
To be a judge, you would need to be a solicitor, chartered legal executive, or barrister with at least 7 years' experience, and you can only get this position through appointment. See:
https://nationalcareers.service.gov.uk/job-profiles/judgeIdeally, you would get an LLB for the solicitor or barrister roles. Do note, a BA in Law is not the same thing as an LLB; LLBs have more law content.
To be a doctor, you would need to do a degree in medicine, a foundation course for residency + how many years' training for your specialism. See:
https://nationalcareers.service.gov.uk/job-profiles/hospital-doctorI am not entirely sure what you mean by Forces Officer. Do you mean police officer or a member of the army?
If you're asking about A Levels for UK degrees, only the degree in medicine will require specific subjects. You can do an LLB in any 3 subjects so long as you have high enough grades.
A number of universities in the UK (and presumably universities outside of the UK that offer medicine at undergrad) would require you to have chemistry and/or biology for degrees in medicine. Your third subject can be in anything you want (if they ask for a third subject for unis outside of the UK).
As such, if you pick Biology, Chemistry, and a third subject (ideally an academic subject) of your choice, you should be fine for any of the 2 degrees above.
In the UK, you don't need qualifications in specifc subjects to join the army (other than the standard GCSEs). Usually A Levels in any subjects are adequate. See:
https://nationalcareers.service.gov.uk/job-profiles/army-officerI don't know what the requirements are in Pakistan though.
Likewise in the UK, you don't need qualifications in specific subjects to join the police force (other the standard GCSEs). A Levels in any subject are adequate. See:
https://nationalcareers.service.gov.uk/job-profiles/police-officerShould you get a degree, it can be a degree in any subject e.g. medicine or law (although a degree in medicine would be overkill for the police force). I don't know what the requirements are in Pakistan though.
Whilst there is a UK degree offered for policing, it's strictly not a required degree for the role and only a handful of universities/colleges offer them.
If you can find a website that shows the job profiles for Pakistan as I have for careers in the UK (National Careers Services:
https://nationalcareers.service.gov.uk/explore-careers), it would make your search a lot easier. I don't know of any Pakistani website for job profiles though, so you might need to google for this.
However, the LLB and medical degrees mentioned above should be valid in Pakistan, although I would check that they would be valid in your country prior to applying at any UK university.