Source

File: wp-admin/includes/nav-menu.php

function wp_nav_menu_taxonomy_meta_boxes() {
	$taxonomies = get_taxonomies( array( 'show_in_nav_menus' => true ), 'object' );

	if ( ! $taxonomies ) {
		return;
	}

	foreach ( $taxonomies as $tax ) {
		/** This filter is documented in wp-admin/includes/nav-menu.php */
		$tax = apply_filters( 'nav_menu_meta_box_object', $tax );
		if ( $tax ) {
			$id = $tax->name;
			add_meta_box( "add-{$id}", $tax->labels->name, 'wp_nav_menu_item_taxonomy_meta_box', 'nav-menus', 'side', 'default', $tax );
		}
	}
}