xslt copy child note and add extra nodes - xslt

Question

For the following xml:
<root>
<employees>
<employee>
<Name>ABC</Name>
<Dept>CS</Dept>
<Designation>sse</Designation>
</employee>
</employees>
</root>
I use this xslt:
<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0">
<!-- Identity transform -->
<xsl:template match="#* | node()">
<xsl:copy>
<xsl:apply-templates select="#* | node()"/>
</xsl:copy>
</xsl:template>
<xsl:template match="Name">
<xsl:copy-of select="."/>
<Age>34</Age>
</xsl:template>
<xsl:template match="Dept">
<xsl:copy-of select="."/>
<Domain>Insurance</Domain>
</xsl:template>
</xsl:stylesheet>
I would like to achieve the following output
<employee>
<Name>ABC</Name>
<Age>34</Age>
<Dept>CS</Dept>
<Domain>Insurance</Domain>
<Designation>sse</Designation>
</employee>
I don't know what xpath shall I use to limit the result only to employee node.

Answer 1

Well, processing starts at the document node (root node) denoted by / thus if you write a template
<xsl:template match="/">
<xsl:apply-templates select="//employee"/>
</xsl:template>
you only process any employee descendants of the document with the rest of the templates.
See https://xsltfiddle.liberty-development.net/pPqsHT6 for a working demo of above suggestion integrated into your stylesheet, the whole code is
<xsl:stylesheet
xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
version="1.0">
<xsl:output indent="yes"/>
<xsl:strip-space elements="*"/>
<!-- Identity transform -->
<xsl:template match="#* | node()">
<xsl:copy>
<xsl:apply-templates select="#* | node()"/>
</xsl:copy>
</xsl:template>
<xsl:template match="Name">
<xsl:copy-of select="."/>
<Age>34</Age>
</xsl:template>
<xsl:template match="Dept">
<xsl:copy-of select="."/>
<Domain>Insurance</Domain>
</xsl:template>
<xsl:template match="/">
<xsl:apply-templates select="//employee"/>
</xsl:template>
</xsl:stylesheet>