Processing of chinese visa by Filipino passport holder in saudi arabia

You can apply for a tourist L type to visit him in PRC. The required documents include your passport and copy of its data page, the application form and a recently-taken passport-style photo, your residence permit in Saudi Arabia, and invitation letter from your friend. Maybe proof of your financial support is required, too. You should submit your application to Foreign Affairs & Business Service Office, CCSC or Al sandross international Est. to apply for it.
You cannot process it online because there is no such kind of service. You can do it personally or entrust someone else to do it for you.