Hi @thatryan,
Thanks for the question.
Yes this is possible, you will only need to make use of the acf/fields/relationship/query filter and modify the $args array that is used to query the posts in the field.
The code will look like so:
<?php
function my_relationship_query( $args, $field, $post_id ) {
// limit number of posts
$args['posts_per_page'] = 1;
// return
return $args;
}
// filter for every field
add_filter('acf/fields/relationship/query', 'my_relationship_query', 10, 3);
?>
