To have conditional field in PLD

Hi! Experts,

Kindly advice in PLD how to over come from this scenario (for ex. There is a two Product A & B out of that Product A contain only width as Size and Product B contains both length & width size. Now in PLD at repetative header there is a column named "Size" in that if product A is selected in order then only width show to be displayed and if product B is selected then length x Width field value should be displayed.

Please explain if both have over come from this kind of scenario. Thanks in Advance..

Regards,

Krishna