After playing with it a bit here is a setup that works.
Sceenshots:
ACF fields setup
Creating the post
The posts output
And this is the code put into single.php before the end of the have_posts() loop
<?php if ( have_rows( 'flex_holder' ) ): ?>
<?php while ( have_rows( 'flex_holder' ) ) : the_row(); ?>
<?php if ( get_row_layout() == 'repeater_holder' ) : ?>
<?php if ( have_rows( 'repeater' ) ) : ?>
<?php while ( have_rows( 'repeater' ) ) : the_row(); ?>
<?php the_sub_field( 'repeater_field_1' ); ?>
<?php the_sub_field( 'repeater_field_2' ); ?>
<?php endwhile; ?>
<?php else : ?>
<?php // no rows found ?>
<?php endif; ?>
<?php endif; ?>
<?php endwhile; ?>
<?php else: ?>
<?php // no layouts found ?>
<?php endif; ?>
