A doctor supervises surgeries in the hospital and receives a share of the fees, but in some cases the patient does not need surgery

It is not permissible for a doctor to do unnecessary surgery for a patient, because that is transgressing against his body by tampering with it, consuming his wealth unlawfully, causing distress to him and his family, and potentially causing complications that could result from that, in addition to the fact that the doctor is lying and committing a breach of trust.

It is not permissible for you to help him or to supervise the patients in any procedure that you are certain comes under this heading [of being unnecessary]. If you do that, then you are a partner in sin.

The money that you receive for supervising patient care is haraam, and you must return it to the patient if you can find him, otherwise you should give it in charity on his behalf. So you should give it to the poor and needy, or spend it on the public interests of the Muslims. You must also repent to Allah.

Allah, may He be exalted, says (interpretation of the meaning):

{But indeed, I am the Perpetual Forgiver of whoever repents and believes and does righteousness and then continues in guidance} [Taa-Haa 20:82].

In the future, you should refrain from supervising these surgeries, and you should object to them and disavow yourself of them, even if that leads to you giving up working in this hospital.

And Allah knows best.