There really isn't enough information in your original post to give a proper answer to your question, but I'll give a "best guess" about what you are attempting to do:
I think, you would like to have posts (or pages) that are related to the post/page that is presently being displayed, displayed in a box, say in a sidebar.
Assuming these are posts/pages are on your site, why would you not use a Relationship field for this? Then you would basically use the code from the ACF website to build your links to the posts.
* Loop through post objects ( don't setup postdata )
* Using this method, the $post object is never changed so all functions need a second parameter of the post ID in question.
$posts = get_field('relationship');
if( $posts ): ?>
<?php foreach( $posts as $post_object): ?>
<a href="<?php echo get_permalink($post_object->ID); ?>"><?php echo get_the_title($post_object->ID); ?></a>
<?php endforeach; ?>