Dynamically add slug for products - wordpress

Question

We're adding a slug to the product's URL dynamically, like this:
add_filter( 'post_type_link', 'custom_product_link', 1, 2 );
function custom_product_link( $post_link, $post ) {
if ( $post->post_type == 'product') {
//In this point, $post_link is, for example: https://domain.test/business/%vendor_slug%/product-demo/
$vendor = dokan()->vendor->get($post->post_author);
$shop_url = $vendor->get_shop_url();
$pieces = explode("/", $shop_url);
$post_link = str_replace("%vendor_slug%", $pieces[sizeof($pieces)-2], $post_link );
//In this point, previous $post_link is: https://domain.test/business/daniel/product-demo/
}
return $post_link;
}
The URL https://domain.test/business/daniel/ is the store of the vendor ( dokan plugin ), and it's working ok, but when we go to the resultant URL -> https://domain.test/business/daniel/product-demo/ it's returning 404 error code, not found.
In WordPress permalink options, we set following:
We also tried adding:
add_filter('query_vars', 'custom_add_query_vars');
function custom_add_query_vars($qVars){
$qVars[] = "vendor_slug";
return $qVars;
}
add_action( 'init', 'custom_rewrites_init' );
function custom_rewrites_init(){
add_rewrite_rule(
'product/([0-9]+)?$',
'index.php?post_type=product&vendor_slug=$matches[1]',
'top' );
global $wp_rewrite;
$wp_rewrite->flush_rules();
}
But error persists.

Answer 1

Finally I solved by overriding product_cat rule, like following:
In WordPress permalink options, setting following:
/business/%product_cat%/
Updating the code like this:
add_filter( 'post_type_link', 'custom_product_link', 1, 2 );
function custom_product_link( $post_link, $post ) {
if ( $post->post_type == 'product') {
//In this point, $post_link is, for example: https://domain.test/business/%product_cat%/product-demo/
$vendor = dokan()->vendor->get($post->post_author);
$shop_url = $vendor->get_shop_url();
$pieces = explode("/", $shop_url);
$post_link = str_replace("%product_cat%", $pieces[sizeof($pieces)-2], $post_link );
//In this point, previous $post_link is: https://domain.test/business/daniel/product-demo/
}
return $post_link;
}
We can remove the code related to add_filter...query_vars, and also the code related to add_action...init
Summary, we overrided product_cat rule, adding the shop slug instead.