felix-wp-columns.php

functions.php

<?php
add_filter ( 'manage_pages_columns', function($columns) {
    return array_merge($columns, ['internal_note' => 'Interne Notiz']);
});

add_filter ( 'manage_pages_custom_column', function($column, $post_id) {
    if($column === 'internal_note') {
        echo get_field('internal_note', $post_id);
        return;
    }
}, 10, 2);