WordPress edit.php category filter to show only posts from direct category and not posts from it child category

Display posts that have this category (not children of that category), using category id:

$cat_post = new WP_Query( 'category__in=4' ); // you will replace the 4 with your category ID
if( $cat_post->have_posts()){
  while( $cat_post->have_posts()):
    $cat_post->the_post();

    // NOW RIGHT THE CODE AS PER YOUR DESIGN

  endwhile;
}