Is this the final format?
<DATA>
<CONSIGNEE>123</CONSIGNEE>
<ORDERID>PO20000005</ORDERID>
<ORDERTYPE>PO</ORDERTYPE>
<REFERENCEORD>123</REFERENCEORD>
<SOURCECOMPANY>100</SOURCECOMPANY>
<COMPANYTYPE>123</COMPANYTYPE>
<NOTES/>
<CREATEDATE>2020-04-21T00:00:00+03:00</CREATEDATE>
<LINES>
<LINE>
<ORDERLINE>66</ORDERLINE>
<REFERENCEORDLINE>2</REFERENCEORDLINE>
<EXPECTEDDATE/>
<SKU>abc</SKU>
<INVENTORYSTATUS>HOLD-IQC</INVENTORYSTATUS>
<QTYORDERED>10</QTYORDERED>
<MNFVALID/>
<MNFPARTNO/>
<HZRD/>
</LINE>
<LINE>
<ORDERLINE>67</ORDERLINE>
<REFERENCEORDLINE>2</REFERENCEORDLINE>
<EXPECTEDDATE/>
<SKU>def</SKU>
<INVENTORYSTATUS>HOLD-IQC</INVENTORYSTATUS>
<QTYORDERED>11</QTYORDERED>
<MNFVALID/>
<MNFPARTNO/>
<HZRD/>
</LINE>
</LINES>
</DATA>
If so, then this will do it (no template though)...
If not - then it might get you closer to a solution.
Import this flow if its of any use to you...
[{"id":"cec9c0ce.0ed32","type":"inject","z":"5a83b5d5.d4161c","name":"","topic":"","payload":"{\"ORDERID\":\"PO20000005\",\"NOTES\":null,\"CREATEDATE\":\"2020-04-21T00:00:00+03:00\",\"PORDERITEMS\":[{\"ORDERLINE\":66,\"EXPECTEDDATE\":null,\"SKU\":\"abc\",\"QTYORDERED\":10,\"MNFPARTNO\":null},{\"ORDERLINE\":67,\"EXPECTEDDATE\":null,\"SKU\":\"def\",\"QTYORDERED\":11,\"MNFPARTNO\":null}]}","payloadType":"json","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":270,"y":260,"wires":[["f60807d9.8986a8"]]},{"id":"a7b693e5.16c93","type":"debug","z":"5a83b5d5.d4161c","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"false","x":780,"y":260,"wires":[]},{"id":"a861792a.4703e8","type":"xml","z":"5a83b5d5.d4161c","name":"","property":"payload","attr":"","chr":"","x":610,"y":260,"wires":[["a7b693e5.16c93"]]},{"id":"f60807d9.8986a8","type":"function","z":"5a83b5d5.d4161c","name":"prepare for XML","func":"\nvar result = {\n \"DATA\": {\n \"CONSIGNEE\": [\n \"123\"\n ],\n \"ORDERID\": [msg.payload.ORDERID],\n \"ORDERTYPE\": [\n \"PO\"\n ],\n \"REFERENCEORD\": [\n \"123\"\n ],\n \"SOURCECOMPANY\": [\n \"100\"\n ],\n \"COMPANYTYPE\": [\n \"123\"\n ],\n \"NOTES\": [ msg.payload.NOTES ],\n \"CREATEDATE\": [ msg.payload.CREATEDATE ],\n \"LINES\": []\n }\n}\n\nvar lines = msg.payload.PORDERITEMS.map(e => {\n return {\n LINE :\n { \n ORDERLINE : [ e.ORDERLINE],\n REFERENCEORDLINE: [\"2\"],\n EXPECTEDDATE: [ e.EXPECTEDDATE],\n SKU: [ e.SKU] ,\n INVENTORYSTATUS: [\"HOLD-IQC\"],\n QTYORDERED: [ e.QTYORDERED ],\n MNFVALID: [\"\"],\n MNFPARTNO: [ e.MNFPARTNO ],\n HZRD: [\"\"]\n }\n }\n});\nresult.DATA.LINES.push(lines);\nmsg.payloadJS = result;\nmsg.payload = result;\nreturn msg;","outputs":1,"noerr":0,"x":440,"y":260,"wires":[["a861792a.4703e8"]]}]