The lighting on these three portraits are pretty straight forward, and you really should be able to deduce it yourself, just trust your instinct and skills.
Obviously they created a black limbo space, probably by blocking all the windows and turning off all the practical lights, if not in a windowless studio.
The key comes from the camera left and is a semi-soft source to minimize nose shaddow. What shaddow you do see under the chin reveals the height and direction of the key light and the minimal fill (if any). Maybe a white card.
The backlight is from straight behind, except for the bald guy, where it has been lowered and moved to the off key side, to minimize the shine on the top of his head.
Finally, a spot of blue light is projected right behind the subject to create the color effect and seperation from the blackness.
When you're trying to "figure out" the lighting plot of a particular shot, look first at the shaddows; they'll tell you the whole story.