wcml_product_content_label

/*
 * Add this code to the functions.php file of your theme.
 */

add_filter( 'wcml_product_content_label', 'change_field_label', 10, 2 );

function change_field_label( $meta_key, $product_id ) {

	// Change the label of 'new_button_label' field in WCML Translation Editor 

	if ( $meta_key == 'new_button_label' ) {
		return __( 'Translate New Button Label', 'textdomain' );
	}

	return $meta_key;
}