So we know the fictitious St John's Hospital was actually the Langham Place office tower, but when we see Largo leaving on the ground floor, it's another location entirely. So here we see the access road to the main entrance of the Hong Kong Academy for Performing Arts, or APA for short.
This place is the closest thing HK has to Fame (remember that?) and its alumni include various local show business notables including Anthony Wong Chau San (aka Anthony Perry) and...erm...a bunch of glorified Karaoke singers more commonly known as 'Cantopop' singers. The lyric theatre here is always hosting the international touring kiddy shows, so of course I've been here a lot.
In the screen grab you can see the institute's name has been covered up using what looks like a fairly convincing Tung Wah Group of Hospitals hospital name plaque. The Streetview picture is a fairly good match for the film angle for a change.