Buying US Dollars in BDO
First and foremost, you can only buy US dollars or any foreign currencies at your BDO branch of account. They won't sell foreign currency to you if you don't have a BDO account with them.
You need to bring your passport, a photocopy of it and your TIN to complete the transaction. For large amounts, it is better to have the dollars reserved a day prior to your visit. There's no need to bring your round trip plane ticket, your passport will do.
I am used to buying foreign currencies for travel at Czarina. But I find the rates of BDO today very competitive. I still use Czarina from time to time. It's a highly recommended money exchange company and it just so happen that they have 2 branches near where I live. Spell convenience.
You can check the daily money exchange rates of BDO on their website https://www.bdo.com.ph and check Czarina's rate at http://www.czarinaforex.com/.