Add existing nav-menus to an select created by the "Advanced Custom Fields"-plugin #WordPress #ACF

gistfile1.php

<?php

namespace WPSE\realloc;

function my_site_menu( $field ) {
	$field['choices'] = array();
	$menus = get_terms( 'nav_menu', array( 'hide_empty' => true ) );
	if ( is_array( $menus ) ) {
		foreach( $menus as $menu ) {
			$field['choices'][$menu->name] = $menu->name;
		}
	}
    return $field;
}
add_filter( 'acf/load_field/name=nav_menu', __NAMESPACE__ . '\\my_site_menu' );