@nml @v3nt you don’t need an acf function to get this working, although it might be nice to integrate something into the admin its not needed and is fairly easy to do this in your theme with or without using the filter mentioned above.
Here’s how to do without using the filter:
If you wrap the guts of your relationship loop with a conditional using get_post_status() you can exclude or specify at that point. e.g.
<?php
$posts = get_field('relationship_field_name');
if( $posts ): ?>
<ul>
<?php foreach( $posts as $post): // variable must be called $post (IMPORTANT) ?>
<?php setup_postdata($post); ?>
<?php if ( get_post_status() == 'publish' ) :?>
<li>
<a href="<?php the_permalink(); ?>"><?php the_title(); ?></a>
<span>Custom field from $post: <?php the_field('author'); ?></span>
</li>
<?php endif;?>
<?php endforeach; ?>
</ul>
<?php wp_reset_postdata(); // IMPORTANT - reset the $post object so the rest of the page works correctly ?>
<?php endif; ?>
If you don’t setup post data in your loop just use this instead:
<?php
if ( get_post_status($p->ID) == 'publish' ){
// loop code
}
?>
ref: https://codex.wordpress.org/Function_Reference/get_post_status
