An unmistakeable place thanks to its unique ramped entrance from Lock Road. The hotel was recently knocked down (in 2006, the same year I moved to HK) and replaced by the godawful iSquare mall. Prior to being the Hyatt it was originally called The President Hotel and opened for business in 1963.
I'm not sure when it was rebranded as a Hyatt (i.e. so was it still The Preseident or The Hyatt when this film was made in 1975?) but it remained so until its demolition which is when Hyatt moved their main Kowloon-side hotel over to The Masterpiece (above K11 mall). Judging from the screen grabs below, it looks as though the up ramp started at the Peking Road end of the building. In the first screen grab below, the building to the right of the flag poles (to the right of the taxi) is the Universal Commercial Building which still stands, and the doorway immediately behind those flag poles was the basement entrance to Club Tasagore (now Delaney's) whose sign can be seen in films such as Enter The Dragon and The Protector.
Bottom picture shows the down ramp with the buildings of Lock Road on the opposite side of the street. From what I can tell, all of those buildings are still standing.
As an interesting and film-related aside, it was this hotel that served as one of the early meeting places between Bruce Lee and Raymond Chow, and also where Lee was first introduced to Betty Ting Pei. The hotel had a rather famous restaurant bar called Hugo's which seems to have been one of Bruce's favoured watering spots.