Using have_rows() with nested acf fields [closed]

ACF official documentation indicates it should be as simple as using have_rows() again:

if ( have_rows( 'field_1' ) ) {
    while ( have_rows( 'field_1 ' ) ) {
        the_row();

        if ( have_rows( 'field_2' ) ) {
            while ( have_rows( 'field_2' ) ) {
                the_row();

                $value = get_sub_field( ... );
            }
        }
    }
}

Note that if the parent field is a group field, have_rows() will treat it as if it has one row, and you will have to declare the other fields outside the have_rows() loop. This answer is a good reference.