Communication has to be two-sided, in order to be effective. Perhaps your boyfriend simply feels more at ease with people in his own "peer" group. Lots of folk [myself included] find it easier to carry on a conversation with someone they know well. It's possible, too, that he's particularly self-conscious in front of your family and friends because, for instance, he may be overly concerned about the kind of impression he THINKS he's likely to make on them ... be afraid of becoming tongue-tied ... and decides to take the line of least resistance by "retreating into his shell".
Certainly in my experience, it's rare to encounter an inherently anti-social Filipino ... and if I were you, I'd have a talk with your parents, sibling(s) and close friends, and try to persuade THEM to "draw him out" a bit ... make the 'first move' in other words. This will, at least, help your b/f to relax in their company and encourage HIM to establish a more naturally responsive and spontaneous line of communication.