You can program in the same group 2 columns of 10 items. The system will let you use either item from 1 to 20 or only from 11 to 20, using the modifiers 1 or modifiers 2 function under P.O.S. Control / Revenue Center / Item Setup.
Item 1 to 20 of the selection Select modifier. ex: vegetable Select modifier 2. ex: vegetable2