The dumbbell bench press exercise is going to work primarily on developing strength and muscle in the chest area (pectoral muscles), but it is also going to work on the shoulders and triceps. Using dumbbells is little different than using a barbell to bench press, because the athlete must also stabilize the dumbbells as they lower them and press them upwards. It is really important for this basketball exercise that the player knows the correct form, and it is also recommended that a spotter is used.
This video is also going to go over the close grip dumbbell bench press which is going to change the primary muscle being worked to the triceps. The dumbbell bench press movement doesn't transfer over into a specific basketball movement, but it is great for developing upper body strength. Which is important for finishing at the basket, rebounding the basketball, being strong with the ball, etc.