Legal Question in Employment Law in California

Your question is not clear. Your medical information is subject to privilege between your doctor and yourself. However, the fact that you use medical marijuana may not be privileged beyond that. For example, the place you get your medical marijuana is not a pharmacy and there is no legal privilege or confidentiality with anyone in that place or with any other person to whom you disclose your use.

There are circumstances where a doctor might reveal your use to your employer, but I can't say if those might apply in your situation.

Asked and answered before. I guess you didn't like the answer, that a company medical exam is not 'confidential'. .