There seems to be a fair share of Pinoy Facebook groups for moms. Are there any Philippine based Facebook groups specifically for dads?

Most of the groups for moms that I am a member of are all closed or secret groups. so you won't really be able to search for them. You would need someone from the group to send you an invite to join the group. You may check this out https://www.facebook.com/daddysinc/?fref=ts. It's an online community called DAD's INC. Maybe you could start building friendships with co-dads in this community and ask them if they are also members of groups for dads. If you are a blogger, you may want to join this Pinoy Daddy Bloggers Network too. https://www.facebook.com/groups/472806282833887/