content-aggregate_page.php

<div class="content-main">
    <?php

    // check if the flexible content field has rows of data
    if( have_rows('flexible_blocks') ):
         // loop through the rows of data
        while ( have_rows('flexible_blocks') ) : $row = the_row();
            switch (get_row_layout()) {
              case 'inserted_content':
                global $post;
                $post = get_post( get_sub_field('inserted_item') );
                setup_postdata( $post );
                ?>
                <article <?php post_class(); ?>>
                  <div class="aggregate-main">
                    <?php vpa_render_post_object( $post ); ?>
                  </div>
                </article>
                <?php
                break;

              default:
                # code...
                break;
            }
        endwhile;
    else :

        // no layouts found

    endif;

    ?>

  </div>

functions.php

<?php
function vpa_render_post_object( $post ) {
  if( apply_filters( 'dcdc/render_post_object/before', $post ) ) {
    return;
  }
  setup_postdata( $post );
  get_template_part('templates/content', $post->post_type != 'post' ? $post->post_type : get_post_format($post));
  wp_reset_postdata();
}

add_filter( 'dcdc/render_post_object/before', 'vpa_on_before_post_object' );
function vpa_on_before_post_object( $post ) {
  if ( ! vpa_is_approved( $post ) ) {
    echo '<div class="well"><p>Sorry, you are not allowed to see ' . $post->post_title . '</p></div>';
    return true;
  }
  return false;
}

function vpa_is_approved( $post = null ) {
  $_post = get_post( $post );
  global $vpa_levels;
  $acf_level = get_field('access_level', $_post->ID);
  if ( in_array((int)$acf_level, $vpa_levels)) {
    return true;
  }
  return false;
}