What additional documents are needed for a business visa application in Thailand when currently located in China?

A Filipino who applied for a Thai business visa while in China had their application canceled due to inadequate support documents. They initially provided an entry stamp but lack additional documentation like a hotel booking, which may be required to prove their current location. Comments suggest that supporting documents might include a valid China visa, hotel booking confirmation, and potentially proof of business legitimacy such as a company bank statement or employment details.