Best approach would be to make the input file of xml extension and provide values in different xml tags ,so your input would look as:-
<FirstName>John</FirstName>
<LastName>Doe</LastName>
<PhoneNumber>555-555-5555</PhoneNumber>
<EmailAddress>jdoe@email.com</EmailAddress>
In your ES2 process, make one input variable of type document for taking this xml file. Now once this document (xml) type file comes in ur process. then use SetValue component to convert the content type of this document to "application/xml".
e.g. Input variable name is "inXMLDoc" of type document which would be consuming xml file from watched folder. Also make one more process variable "inXML" of type xml. Now in SetValue , in location type "/process_data/@inXML" and in expression type "setContentType("/process_data/@inXMLDoc","application/xml")".
So through this you can get your xml file in xml variable named inXML and retrieve content of it using XPath.
Let me know if it resolves ur problem.
Thanks,
Prashast