Query ACF Repeater Field with embedded Group

<!--REPEATER-->
<?php if( have_rows('repeater') ): ?>
    <?php while( have_rows('repeater') ): the_row(); ?>
    <!--GROUP-->
        <?php if( have_rows('group') ): ?>
           <?php while( have_rows('group') ): the_row(); 
                // vars
                $title = get_sub_field('title'); ?>

                <?php echo $title; ?>
            <?php endwhile; ?>
        <?php endif ?>
        
    <?php endwhile; ?>
<?php endif ?>