XML data fiter in SAP HCI

Dear Experts-

I have an issue with extracting certain data and send the data to XSLT mapping. I am doing a real time query to API using a Survey Key to fetch the results. I am generating multiple files which has following 2 of data in separate files..

Data 1 which works fine with my XSLT mapping as it has results for the survey key.

<?xml version='1.0' encoding='UTF-8'?>

<Root>

<Element>

<SK>319010</SK>

</Element>

<Element>

<meta/>

<data>

<ts>2017-12-01T14:12:58.000-08:00</ts>

<r>0</r>

</data>

<data>

<ts>2017-12-01T14:12:59.000-08:00</ts>

<r>0</r>

</data>

</Element>

</Root>

Data 2 which my XSLT map fails because no data for particular survey key.

<?xml version='1.0' encoding='UTF-8'?>

<Root>

<Element> <SK>216621</SK>

</Element> <Element>

<meta/>

<data/>

</Element> </Root>

I need to filter the data before sending it to map in a way that I will send only survey key data which has results. I am trying to use Filter and Router in HCI but am not successful. This is really urgent as have golive in 2 days. If you can help to get this through it would be much appreciated.

Regards

HS