You can use the exportData from the Form Data Integration service to extract the data from a PDF.
It'll put the result into a "document" variable. Then you can use a setValue operation to put the content of the document variable into a XML variable and use xPath to get to the data element you need.
I already tried it. I've gotten xml variable which includes all data but I didn't success to get the data element from it using xPath. I tried to navigate to data element like usually but it doesn't work.
If you're using Form Data integration to extract the XML data from your form variable, then it will include additional XDP envelope elements. You can use removeXDPEnvelope in this component to remove the XDP envelope, and turn it into regular XML.