In case you wish to show unit attachment in Unit
—
add_filter(‘wplms_curriculum_course_lesson’,function($title,$unit_id){
$attachments = get_post_meta($unit_id,’vibe_unit_attachments’,true);
if(!empty($attachments)){
foreach($attachments as $attachment_id){
$title .=’ <a class=”has-primary-color” href=”‘.wp_get_attachment_url($attachment_id).'” target=”_blank”>Preview</a> ’;
}
}
return $title;
},10,2);
refer how to add code customisations : link