Import specific fields from XML file

One way to do this is to have two templates in your XSLT: one that copies everything from the source to the destination as-is and one that removes everything but the elements you specify.

For example, if, say, I wanted to only keep the root element, <fieldToKeep1> and <fieldToKeep2> from such a document, the XSLT basis for doing this might look like:

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0">
  <xsl:output omit-xml-declaration="no" indent="yes"/>
  <xsl:strip-space elements="*"/>

  <xsl:template match="@*|node()">
    <xsl:copy>
      <xsl:apply-templates select="@*|node()"/>
    </xsl:copy>
  </xsl:template>

  <xsl:template
    match="*[not(
             contains(
               '|rootElement|fieldToKeep1|fieldToKeep2|',
               concat('|', name(), '|')
             )
           )]" />

</xsl:stylesheet>

I like this approach because, should you require other fields be kept, you can simply modify the |fieldToKeep1|fieldToKeep2| string to include the elements you want. Again, this is a basis and would probably need to be modified for your specific example.