Can I set toplevel config options in a submodule?

If I define a module with submodule:

  { config, lib, ... }: {
     options.whatever = {
         sub = mkOption {
             default = {};
             type = with lib.types; attrsOf submodule (
               { name, ...}: {
                  options = {
                     ...
                     ...
                  };
                 config = {
                   # Can I define topLevel config here?
                 };
         };
     };
  }

No, you should do another top level option that depends on sub option