If you are trying to read Component Link related text fields on XSLT Component Template.
You can perform as below,
<!-- Gets the Component Link Uri -->
<xsl:variable name="abcLink" select="/tcm:Component/tcm:Data/tcm:Content/ref:XYZ/ref:ABCLink/@xlink:href" />
<!-- Gets the Content of Link Component -->
<xsl:variable name="abcLinkField" select="document($abcLink)/tcm:Component/tcm:Data/tcm:Content/ref:ABC" />
<!-- Prints "A" field related content -->
<xsl:value-of select="$abcLinkField/ref:AField/text()" />
<!-- Prints "B" field related content -->
<xsl:value-of select="$abcLinkField/ref:BField/text()" />
<!-- Prints "C" field related content -->
<xsl:value-of select="$abcLinkField/ref:CField/text()" />
Here document($abcLink)
invokes the protocol handler to get the linked item through the URI specified, and from there onwards you can simply proceed as with any item
xlink
element, so you can read itshref
attribute and find the TCMURI