Hello Rei,
Reinholds suggestion will provide you with a hierarchy inside the BO instance.
So, you need only one BO for the whole hierarchy and the ChildNode has the association to the RegisteredProduct.
You can also model the hierarchy with BO instances. I.e. the BO will look like this
businessobject BusinessObject1 {
[AlternativeKey] element ID:ID;
element ParentID:ID;
association Children [0,n] to BusinessObject1 valuation (ParentID == ID);
}
The difference here is that the association which defines the hierarchy is at Root node level.
Thomas Schneider described it also in his blog (http://scn.sap.com/community/business-bydesign/studio/blog/2012/01/09/sap-business-bydesign-studio-application-development#jive_content_id_1n_Associations_and_Association_Valuations_FP40).
So you can choose which you prefer.
HTH,
Horst
