It doesn't work :-( If I use a xml like that :
<root><entry><One><y>813</y><x>270</x></OnePeak></entry><entry><One><y>890</y><x>280</x></OnePeak></entry></root> and the following provider : {xmlData.entry.One} I cann display all the points, but as if it was one series and note two. Alternativly, I can specify entry[0] or 1 to display one or the other series but one more time not both...