XSLT group every nth item in to new group - xslt

Question

I have done few XSLT in the past, but I am facing challenge in this.
I am working with PLC tag, for each tag i am getting three rowset node, so after every three Rowset i need to create new "Row" group.
Updated with XSLT
Input XML:
<?xml version="1.0" encoding="UTF-8"?>
<Rowsets >
<Rowset>
<Row>
<DateTime>2021-07-05T07:33:38</DateTime>
<WC_ID>0001</WC_ID>
</Row>
</Rowset>
<Rowset>
<Row>
<DateTime>2021-07-05T07:33:38</DateTime>
<Tag1_Good>6817</Tag1_Good>
</Row>
</Rowset>
<Rowset>
<Row>
<DateTime>2021-07-05T07:33:38</DateTime>
<Tag1_Bad>0</Tag1_Bad>
</Row>
</Rowset>
<Rowset>
<Row>
<DateTime>2021-07-05T07:33:38</DateTime>
<WC_ID>0002</WC_ID>
</Row>
</Rowset>
<Rowset>
<Row>
<DateTime>2021-07-05T07:33:38</DateTime>
<Tag2_Good>6800</Tag2_Good>
</Row>
</Rowset>
<Rowset>
<Row>
<DateTime>2021-07-05T07:33:38</DateTime>
<Tag2_Bad>0</Tag2_Bad>
</Row>
</Rowset>
</Rowsets>
Expected output:
<?xml version="1.0" encoding="UTF-8"?>
<Rowset>
<Row>
<WC_ID>0001</WC_ID>
<Tag1_Good>6817</Tag1_Good>
<Tag1_Bad>0</Tag1_Bad>
</Row>
<Row>
<WC_ID>0002</WC_ID>
<Tag1_Good>6800</Tag1_Good>
<Tag1_Bad>0</Tag1_Bad>
</Row>
</Rowset>
My XSLT:
<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:template match="/">
<Rowsets >
<xsl:variable name="batchSize" select="3"/>
<Rowset>
<xsl:for-each select="/Rowsets/Rowset[position() mod $batchSize >= 0]"
<Row>
<xsl:value-of select="Row/*[2]" />
</Row>
</xsl:for-each>
</Rowset>
</Rowsets>
</xsl:template>
</xsl:stylesheet>
I am not able to make this into a new group

Answer 1

Use this:
<Rowsets>
<xsl:variable name="batchSize" select="3"/>
<Rowset>
<xsl:for-each select="/Rowsets/Rowset">
<xsl:variable name="pos" select="position()"/>
<xsl:if test="$pos mod $batchSize = 0">
<Row>
<WC_ID>
<xsl:value-of select="/Rowsets/Rowset[$pos - 2]/Row/*[2]"/>
</WC_ID>
<Tag1_Good>
<xsl:value-of select="/Rowsets/Rowset[$pos - 1]/Row/*[2]"/>
</Tag1_Good>
<Tag1_Bad>
<xsl:value-of select="/Rowsets/Rowset[$pos]/Row/*[2]"/>
</Tag1_Bad>
</Row>
</xsl:if>
</xsl:for-each>
</Rowset>
</Rowsets>