How do I apply for tourist visa to hongkong, if I'm a bangladesh national residing in the manila?

You may just apply for the Hk visa through the China Embassy in Philippines. The requirements are:
1. The original passport of the applicant
2. a completely filled Hk visa application form ID 1003A
3. The applicant's recent photograph affixed on page 1 of the application form ID 1003A
4. Photocopy of the applicant's travel document containing personal particulars, date of issue, date of expiry and/or details of any re-entry visa held (if applicable)
5. Photocopy of proof of the applicant's financial standing, such as bank statement, savings accounts passbooks, tax receipts. If your boss will sponsor the trip, provide your boss'.
6. flight itinerary
7. proposed leisure visit to Hong Kong, e.g. receipt of joining a package tour to Hong Kong, itinerary