They can apply for a schengen visa in the Philippines.
http://www.ambafrance-ph.org/france_...php?article195
If it is granted they could then travel to France/Belgium from the UK. The fact you are a British Citizen doesn't really them help get a Schengen visa, though if they have already been granted a UK visit visa that may help them. One problem you may have is that when applying for Schengen visas they often want to see actual bookings (hotel/travel).