Custom Post Types and Complex Content Hierarchy

Question

I'm developing a fairly complex portfolio WP theme and I can't seem to figure out the logical and most efficient way to setup hierarchy for content. The content needs a deep hierarchy and I need breadcrumbs and menus to work. The custom post type(CPT) is used for "client work" which ideally would be a sub-page of Work >> Clients >> Client (CPT) in the default Pages structure. But I can't define a Parent page for CPT's. I'm rewriting the slug accordingly but this doesn't seem to maintain the parent/child relationship.

Currently, I have things structured like this:

Work > Clients >> Client >>> Client Work(CPT) >>> Single Work Item

My questions are: 1. Is there a better way to structure this? 2. Should I not use CPT's or how can a I add CPT's into more of a hierarchical structure so they relate to their respective parents?

Here is my CPT registration code:

class cpt_client_work {

function cpt_client_work() {
    add_action('init',array($this,'create_post_type'));
}

function create_post_type() {
    $labels = array(
    'name' => 'Client Work',
    'singular_name' => 'Client',
    'add_new' => 'New Client Work',
    'all_items' => 'All Client Work',
    'add_new_item' => 'New Client Work',
    'edit_item' => 'Edit Client Work',
    'new_item' => 'New Client Work',
    'view_item' => 'View Client Work',
    'search_items' => 'Search Client Work',
    'not_found' =>  'No Client Work found',
    'not_found_in_trash' => 'No Client Work found in trash',
    'parent_item_colon' => 'Parent Client:',
    'parent' => 'Client',
    'menu_name' => 'Client Work'
    );
    $args = array(
        'labels' => $labels,
        'description' => "Client Work",
        'public' => true,
        'exclude_from_search' => false,
        'publicly_queryable' => true,
        'show_ui' => true, 
        'show_in_nav_menus' => true, 
        'show_in_menu' => true,
        'show_in_admin_bar' => true,
        'menu_position' => 20,
        'menu_icon' => get_bloginfo('template_directory') . '/_/images/admin-icon.png',
        'capability_type' => 'post',
        'hierarchical' => true,
        'rewrite' => array('slug' => 'work/client'),
        'supports' => array('page-attributes','title','editor','thumbnail','excerpt','custom-fields','revisions','author'),
        'has_archive' => true,
        'query_var' => true,
        'can_export' => true
    ); 
    register_post_type('cpt_client_work',$args);
}
 }

Answer 1

You are trying to put Works and Clients on the same level and this is a little confusing. I would suggest you to keep the two entity separeted and the make all the relationship you need with the mentioned Posts to posts plugin.

First of all, create a custom type Work with his own slug ():

...
function create_post_type() 
{
    $labels = array( 
        'name' => 'Work',
        ...
    );
    $args = array(
        'labels' => $labels,
        'rewrite' => array('slug' => 'works'),
        ...
    ); 
    register_post_type('work',$args);
}
...

Then create the Clients:

...
function create_post_type() 
{
    $labels = array( 
        'name' => 'Clients',
        ...
    );
    $args = array(
        'labels' => $labels,
        'rewrite' => array('slug' => 'clients'),
        ...
    ); 
    register_post_type('client',$args);
}
...

Now install the Posts to posts plugin and define the relationship between the two entities:

function my_connection_types() {
    p2p_register_connection_type( array(
        'name' => 'works_to_clients',
        'from' => 'work',
        'to' => 'client'
    ) );
}
add_action( 'p2p_init', 'my_connection_types' );

At this point, your data structure is well built and you can move to the next stage (Clients and Works themes, breadcrumb, etc.)