How do i show wordpress attachments from current post?

Your code and description seem to refer to the previous/next attachment navigation. That code is intended to display previous/next attachment navigation, and that’s exactly what it’s doing.

If you want to display all attachments:

1. Within the Post Content, use the shortcode

2. Programmatically, in the template file, use e.g. get_posts(), combined with e.g. wp_get_attachment_image():

   <?php
   global $post;
   $attachment_images = get_posts(
       'post_type' => 'attachment',
       'post_parent' => $post->post_parent,
       'post_mime_type' => 'image'
   );
   // Output images
   ?>
   <ul>
   <?php
   foreach ( $attachment_images as $attachment_image ) {
       // Output images here. Note that get_posts()
       // returns an array of OBJECTS, so the ID
       // would be $attachment_image->ID
       echo '<li>' . wp_get_attachment_image( $attachment_image->ID, 'thumbnail' ) . '</li>';
   }
   ?>
   </ul>