constraint siebel message based on Child/Grandchild condition

Hi,

I am working on a scenario where i need to generate a siebel message based for the IO where Account is the Root IC , Account has one child as Order, Order has one child Order Item.

I need to get siebel message which contains only those cases where order Item contains a particular Part Number(IC field). I ran EAI Siebel adapter with the searchspec as "Item.Part# = XYZ" , and got the records where the order items contains Part Num as XYZ however I am also getting those records where no order item contain part num XYZ, In these cases the Account and Orders section has information populated but the order item hierarchy is empty.