I’m trying to customize the permalink of some child pages.

I have this structure:
example.com/story/story-name-slug/chapter-slug/page-slug

And I’m trying to transforming that structure into this:
example.com/section/page-slug

But also I want to keep the other links active, so in the end I should have the following:
example.com/story -> archive of all story;

example.com/story/story-name-slug -> list of all chapters;

example.com/section/page-slug -> page with customized url.

Keep in mind that example.com/story/story-name-slug/chapter-slug is not a page that can be visited by users. It’s only used to archive the hierarchical relation between pages.

At the moment I got the url structure working with the following code in functions.php:

add_filter('page_link', 'custom_permalink', 10, 3);
add_filter('page_type_link', 'custom_permalink', 10, 3);

function custom_permalink($permalink, $post_id) {

    $post = get_post($post_id);

    $post_name = $post->post_name;

    $id_chapter = $post->post_parent;
    $id_story = wp_get_post_parent_id($id_chapter);
    $id_stories = wp_get_post_parent_id($id_story);

    if ($id_chapter !== 0 && $id_story !== 0 && $id_stories ) {
        // the static base url is just for testing
        $permalink = 'example.com/section/' . $post_name ;
    } else {
        $permalink = $permalink;
    }

    return $permalink;
}

This works but not as it shoudl, I get the right URLs on the right pages but when I visit those pages I get a 404 Error not found.

After some digging in the sql queris that get executed I think that the problem is that WP is selecting wp_posts.post_type="attachment" instead of wp_posts.post_type="page".

I think that a rewrite rule is needed somewhere to specify in the sql query what to select, but this goes over my current capabilities.

If it’s needed I can provide all the queries that get executed on the page with and without the filter that I added.

Thanks!