Hi Niek,
You can apply splitByValue function to each of the <D> nodes, <C> nodes and <B> nodes and try.
You can check the scn on splitByValue function here:
http://help.sap.com/saphelp_nwpi71/helpdata/EN/21/3bb8c495125e4eb5969f0377885fe0/content.htm
It depends on the structure of response expected and you can use split by value function with each context/value set properly and try.
Regards,
Ramya