I produced a area using the Adv Custom Fields wordpress plugin which enables the consumer to choose which section the page is under (like groups). On each page Let me display a sidebar which shows a listing of pages with similar section. Cleaning it once a to make use of meta_query and that i do not get any improvements. I'd like to show parents page first if there's a method to get it done. Here's my query:

<ul class="test-menu">
<?php 
   $section = get_field('section'); 

   $args = array(
      'meta_query' => array(
         array(
            'key'    => 'section',
            'value'  => $section
         )
      )
   );

   $loop = new WP_Query( $args );

   while ( $loop->have_posts() ) : $loop->the_post();
   ?>

      <li><a href="<?php echo get_permalink(); ?>"><?php the_title(); ?></a></li>

   <?php endwhile; ?>

   <?php wp_reset_query(); ?>
</ul>

Appears like you have to specify a publish_key in your query and you're simply missing the compare bit although I am unsure which throw you off :

$args = array(
      'post_type' => 'post',
      'meta_query' => array(
         array(
            'key'    => 'section',
            'value'  => $section,
            'compare' => "="
         )
      )
   );

The publish type can most likely be an assortment for those who have multiple kind of custom posts.