Product Configuration: Restrict 1 Product per Order

Hi,

I am trying to look into a requirment:

Requesrment: User should not select more than 1 product per Order.

Example: Product Structure - Parent: ProductAAA , Child : Product XYZ1 , Product XYZ2, ProductXYZ3 etc

Order Line Items: I can have more than one ProductAAA (Parent) in an Order, but cannot have more than one Product XYZ1.

I want to try this in Products Configuration level (non srf change).

Appreciate you help.

-Eswar