The money supply is all the currency and other liquid instruments in a country's economy. It can be compiled into 3 measures, M1, M2 and M3. Different countries have slightly different definitions of M1, M2 and M3.
For the case of Hong Kong:
M1 = currency in circulation + demand deposits
M2 = M1 + saving deposits with licensed banks + time deposits with licensed banks + negotiable certificates of deposits (NCDs) issued by licensed banks
M3 = M2 + deposits with restricted licensed banks and deposit-taking companies + negotiable certificates of deposits (NCDs) issued by restricted licensed banks and deposit-taking companies
For the case of other countries, refer to:
https://www.hkma.gov.hk/media/eng/publication-and-research/quarterly-bulletin/qb200205/fa02.pdf