Fractional First Officer reported the Captain conducted a visual approach to the wrong runway resulting in terrain warnings.

Narrative

Arrival into ZZZ after dark on a clear night I had programmed in the company Visual XXR as the winds were 160 at 8. The pic briefed the approach from my iPad after I pulled up the plate for him. He asked several questions about things he didn't understand which we walked through and I pointed out to him on different places on the approach plate as well as the moving map and vertical situation display on the airplane. Once we got the field in sight I asked if he wanted me to call it to atc so we could join the visual from the fix we had been vectored to by ATC. He agreed so I called it and we were cleared for the visual and given a bravo clearance. I ask him if he would like direct to ZZZZZ and he agrees so we start in that direction. Immediately after we make the turn aligning us with XYL he starts immediately changing altitude and saying that this doesn't look right we are too high when in fact we are below the path at the time. He immediately puts the airplane in a steep descent calling for flaps 1; gear; and flaps two as well as deploying the speed brakes as he dived below the minimum altitudes on each of the fixes. I say that we are getting to low and very close to the mountains. He continues to decide and I tell him that we are to low and going to set off the GPWS (Ground Proximity Warning System). He does not stop his descent and then he realizes that he is diving for XYL and not even flying the approach for XXR. In a matter of seconds from the beginning of this we get the to low flaps" and the "check runway" warnings from the airplane he asks for flaps full which I select. We land on runway XYL make the left turn off the runway and go to the ramp. There must be a system put in place for people particularly FOs (First Officer) to express safety concerns to either the company or the union that can address problems with PICs without fear of being caught in the middle of something. The PIC has absolutely no idea how any of our charted visuals are supposed to be flown even when he is more aware of his surroundings. He has been far behind all week long and repeatedly spaces out and becomes disoriented. Age is undoubtedly a factor but he has expressed numerous times that he has no desire to utilize the technology in the airplane or the procedures developed to do things he feels he can do with guesswork and many years of experience."