When I click on add new post hidden link, I'm redirected to the page hidden link with the sufix ?parent_supplier_id=4661
It works well, I can't select other than the father where it comes from ?parent_supplier_id=4661
But if I go to the page hidden link I could create a post that is related to any father, and this is not allower buy business rules, only from the father it cames from
Hello. Thank you for contacting the Toolset support.
You used both version one version where you are passing the parent ID and with another version you are not passing the parent ID.
I'm not sure what the issue here, once you have parent ID, the passed parent ID will be automatically selected, I'm not sure as you said, its working but what changes you want there.
If you do not want to stick with any parent you should go with option (where you are not specifying any parent in the URL) : hidden link