find_playable_relatives_effect

find_playable_relatives_effect = {
	if = {
		limit = {
			any_close_family_member = { playable_relative_trigger = yes }
		}
		ordered_close_family_member = {
			limit = { playable_relative_trigger = yes }
			order_by = highest_held_title_tier
			max = 3
			check_range_bounds = no
			if = {
				limit = { exists = scope:alt_2 }
				save_scope_as = alt_3
			}
			else_if = {
				limit = { exists = scope:alt_1 }
				save_scope_as = alt_2
			}
			else = { save_scope_as = alt_1 }
		}
	}
}

As written in game/common/scripted_effects/07_dlc_ep3_scripted_effects.txt.