charting_the_realm_perk_effect

charting_the_realm_perk_effect = {
	if = {
		limit = {
			has_perk = realm_charts_perk
			OR = {
				NOT = { has_variable_list = mapmaking_location_list }
				NOT = {
					is_target_in_variable_list = {
						name = mapmaking_location_list
						target = location
	 				}
				}
			}
			exists = location.county
			location = { has_holding = yes }
			OR = { #We save domain provinces, top lieges capital or direct vassals capitals at count tier or over - always by link comparisons
				AND = {
					location.county.holder = root
					location.county != location.county.holder.capital_county
				}
				AND = {
					top_liege != this
					location.county.holder != root
					root.top_liege = location.county.holder.top_liege
					location = location.county.holder.top_liege.capital_province
				}
				AND = {
					location.county.holder != root
					location.county.holder.liege = root
					location = location.county.holder.capital_province
				}
			}
		}
		add_to_variable_list = {
			name = mapmaking_location_list
			target = location
		}
	}
}

As written in game/common/scripted_effects/00_wanderer_lifestyle_effects.txt.