Laravel Nova Disabling Create Button

When I want to disable create button in nova resource, I know two options:

• Using Laravel Policy
• authorizedToCreate method within the resource.

But using policy in nova resource, you don't have access to whatever resource you're dealing with, only the Authenticated User.

public function create(User $user)
{
    return $user->isAdmin();
}

The same goes to authorizedToCreate method within the resource, only the Request passed to the method.

Having Post model and Comment model that belongs to post, how can I disable the create button in laravel nova depending on the Post status?