Hi @hube2 i already fix the error i mentioned above and your code work like a charm. Thank you so much for your amazing help your such a big help to this community. I might need more help in the future because mostly e use ACF on our website.
Once again thank you so much.
Here the final code
`add_filter(‘acf/fields/relationship/query/name=related_tracks_certificate’, ‘remove_already_selected’, 10, 3);
function remove_already_selected($args, $field, $post_id) {
$query = new WP_Query(array(
‘post_type’ => ‘Tracks’, // my assumption
‘post_status’ => ‘publish’,
‘posts_per_page’ => -1
));
$selected = array();
if (count($query->posts)) {
foreach ($query->posts as $post) {
$tracks = get_field(‘related_tracks_certificate’, $post->ID, false);
if (!empty($tracks)) {
foreach ($tracks as $track) {
$track = intval($track);
if ($track && !in_array($track, $selected)) {
$selected[] = $track;
}
} // end foreach track
} // end if tracks
} // end foreach post
} // end if posts
if (!empty($selected)) {
$args[‘post__not_in’] = $selected;
}
return $args;
} // end function
