Again, that gets into how a college classifies (and for what purpose) versus, as an example, a census definition. A college may want to have a category comprised on descendants of the indigenous people of the US. The US includes the 50 states plus DC as well as several overseas territories. So the indigenous peoples would include Native Americans/Native Alaskans/Native Hawaiians, and also Chamorros and Samoans from American Samoa (but not the country of Samoa). The broader census definition (which some colleges may or may not follow) would also include Fijians, Chuukese, etc.
The Common App, as @privatebanker correctly stated, specifically excludes the Philippines. However, it does allow the applicant to write-in a non_US territory option. The exact question on the CA is:
Anyway, bottom line, there’s no organization in the US that would include Filipinos as Pacific Islanders.