pam_potential_secular_clerical_split_ruler_trigger

pam_potential_secular_clerical_split_ruler_trigger = {
	$RULER$ = {
		is_alive = yes
		is_landed = yes
		faith = scope:actor.faith
		NOR = {
			this = scope:recipient
			trigger_if = {
				limit = { exists = scope:recipient.liege }
				this = scope:recipient.liege
			}
		}
		highest_held_title_tier >= tier_duchy
		NOT = { pam_government_is_religious_playable_trigger = yes }
		capital_county = {
			exists = clerical_region_title
			clerical_region_title.holder = scope:recipient
			# We always keep the region capital, because splitting it off would leave the new region with no capital
			NOT = { this = clerical_region_title.title_preferred_capital_county }
		}
	}
	# any_sub_realm_county, not any_realm_county: for a vassal the latter is the liege's whole realm
	trigger_if = {
		limit = { scope:recipient = scope:actor }
		$RULER$ = {
			NOT = {
				any_sub_realm_county = {
					any_neighboring_county = { this = scope:recipient.capital_county }
				}
			}
		}
	}
}

As written in game/common/scripted_triggers/pam_scripted_triggers.txt.