Glad I found this thread! I was trying to combine a relationship field and have that place a pin on the map. Here’s the code I have that works for me:
<?php $posts = get_field('featured_space'); if( $posts ): ?>
<div class="acf-map">
<?php foreach( $posts as $post): // variable must be called $post (IMPORTANT) ?>
<?php setup_postdata($post); ?>
<?php $space_address = get_field('space_address', $post->ID); ?>
<div class="marker" data-lat="<?php echo $space_address['lat']; ?>" data-lng="<?php echo $space_address['lng']; ?>">
<h4><?php the_title();?></h4>
<p><?php echo $space_address['address']; ?></p>
</div><!--/.marker-->
<?php endforeach; ?>
<?php wp_reset_postdata(); // IMPORTANT - reset the $post object so the rest of the page works correctly ?>
</div><!--/.acf-map-->
<?php endif; ?>
Or if that does not work here’s a link to a gist with the code: Gist
