When I was in high school, the control panel on the BMT standards had, I believe, 8 buttons in two rows, like:
o O o
o o o o o
The top row were the "open" buttons. The large one in the center
opened all side doors (in all cars), the smaller ones on the sides, IIRC, opened the end doors (between the cars).
The bottom row were the "close" buttons. The far end ones were
for the car-end doors, the middle/left and middle/right were for all side doors to the left or right of the Conductor's postion, and the center button was for the set of doors at the Conductor's control panel.
Now, I'm remembering from over 35 years ago, so I could be wrong.