/**
 * Hide R1 field for customers outside HR
 **/
add_action( 'woocommerce_after_checkout_form', 'mx_show_r1_4hr' ); 
function mx_show_r1_4hr(){
     if ( is_checkout() ) {
    ?>
 
    <script>
        jQuery(document).ready(function($){
						
			$(document).on('updated_checkout', function(){
				if ($('#billing_country').find('option:selected').val() == 'HR'){
					 $('#mx_custom_checkout_field').show();
				} else {
					$('#mx_custom_checkout_field').hide();
				}
			});
 
 
        });
    </script>
 
    <?php
     }
}