I was able to get this figured out through a couple stack exchange forums. I did not end up using an ACF field because I wasn’t sure at the time. Essentially I have a rewrite rule hooked to init and post_type_link that uses the meta value of my custom field (which I imagine can be done with ACF as well. Here’s some of the code:
/* Add rewrite rules for permalink structure */
add_action( 'init', array( $this, 'map_rewrite_rules') );
add_filter( 'post_type_link', array( $this, 'filter_map_permalik'), 10, 2 );
public function setup_map_meta_boxes() {
add_meta_box('story-map', 'Map Series', 'story_attributes_meta_box', 'story', 'side', 'default');
}
public function map_rewrite_rules() {
add_rewrite_rule( '(.*)/([^/]+)/?$','index.php?story=$matches[2]','top' );
}
I made the custom field like so:
function story_attributes_meta_box($post) {
$pages = wp_dropdown_pages(
array(
'post_type' => 'map',
'selected' => $post->post_parent,
'name' => 'parent_id',
'show_option_none' => __('(no parent)'),
'sort_column' => 'menu_order, post_title',
'echo' => 0
)
);
if ( ! empty($pages) ) {
_e('<label class="fat-wide">Map: </label>');
echo $pages;
}
}
Hope that can help you on your project in some way
