A Better Tomorrow II (1987) on Netflix

Ho was serving time for killing the enemy gang boss at the end of "A Better Tomorrow" when he found out that his younger police brother, Kit, has gone undercover as Billie in order to infiltrate shipbuilding business head by Lung. Ho decided to join the investigation by going undercover as well. Police suspect counterfeit dollars are produced in the business. Kit's wife is pregnant and birth is expected very soon, but Kit has to put that aside in order to seduce Lung's daughter Peggy. However, a hitman killed a rival gang leader while Lung was holding a gun, forcing Ho to smuggle Lung out of Hong Kong and hide in New York. Meanwhile, in New York, Ken, twin brother of Mark (from "A Better Tomorrow"), is operating a Chinese restaurant and dealing with local Mafia intend to setup racketeering operations. The real culprit in Hong Kong actually was Lung's right-hand-man Ko who bought the hitman off to frame his own boss, so Ko can take over the business. Ko tipped off the New York Mafia. The mafia then did a hit on the church, killing the priest and many church members, and an innocent girl died in Lung's arms. Lung was driven insane when he realized his daughter is dead, and he was committed to a psychiatric hospital. Ken happened by the hospital and rescued Lung. Ken's restaurant was blown up by the Mafia, and another attempt on Lung's life failed when Ken turned out to be just as good as Mark in gun battles. When Ken was wounded in the gun battle/chase, Lung snapped out of his insanity and was able to help Mark take care of the enemies. Lung and Ken then returned to Hong Kong and linked up with Ho and Kit to plot revenge on Ko. Their first attempt to expose Ko went awry when they hit the wrong target. Kit was able to find the right target: Ko's mansion, but was mortally wounded by the hitman, just as his wife gave birth to a baby girl. Ho, Ken, and Lung vowed revenge. They will deal with traitorous Ko and his army of mercenaries, including the hitman... or die trying...