Which bus to take from Shamrock Hotel in Nathan to Hong Kong Airport

Shuttle bus no. A22 helps. Walk from your hotel to Woosung Street, Jordan Road to take that to HKIA directly. As I know, the first bus leaves the starting station around 05:30.

Well, it takes around 40min from the boarding station to HKIA, so you may consider whether you can catch your flight.

If you really intend to take the bus, make sure you check in ahead in the city to save time.