PI Mapping : Merge data from difference node into 1 node

Dear Expert,

          I have problem to merge data from difference node into one like below example.

          Source :

          <Order>

               <DoneOrder>

                         <Product>Mat1</Product>

               </DoneOrder>

               <DoneOrder>

                         <Product>Mat2</Product>

               </DoneOrder>

               <PendingOrder>

                    <Produce>

                         <Produce>Mat3</Produce>

                    <Produce>

                    <Produce>

                         <Produce>Mat4</Produce>

                    <Produce>

               </PendingOrder>

          </Order>

          Target :

          <Root>

               <AllOrder>

                    <rows>

                         <Product>Mat1</Product>

                    </rows>

                    <rows>

                         <Product>Mat2</Product>

                    </rows>

                    <rows>

                         <Product>Mat3</Product>

                    </rows>

                    <rows>

                         <Product>Mat4</Product>

                    </rows>

               <AllOrder>

          </Root>

          Could you please suggest the solution for this transformation this message? (It will be good if not use UDF)

          Thank you very much!!