i need help tofind the parents of my grandfather francisco del rosario 1880-1970, born in obando bul

Another method that may help is to find the person who was the root (early genus) of your surname with his family and save it to Add Unconnected Person in the Family Tree <How do I add an unconnected person to Family Tree?>. Then share the URL of that person to your relatives, same surname group, and so on, so that they can help adding some descendants connected to his family. Possibly that there may be a line that leads to your ancestor.