Sorry, I try this, but still not work.
<?php
if ( is_singular( 'playlists' ) ):
$current_category = get_field( 'categorias', get_the_ID() );
if( have_posts() ): ?>
<ul>
<?php while ( have_posts() ) : the_post();
if (get_field('categorias') == $current_category): ?>
<li>
<a href="<?php the_permalink(); ?>">
<img src="<?php the_post_thumbnail('thumbnail'); ?>" />
</a>
</li>
<?php endif; ?>
<?php endwhile; ?>
</ul>
<?php endif; // have_post ?>
<?php endif; //is_singular ?>