Drop Downs Need Parameters

When entering a sub invoice after selecting the subcontractor the menu does not limit the available job cost codes to the one that are only for that vendor. It has all available. This causes major accuracy issues when all job cost codes even outside what is available on the prime contract be available. Please limit the drop down menus everywhere to only be applicable field options based on how the module is used and codes being selected in various parts of the process (subcontracts, POs, etc.). Thank you