xslt how to get value from an xml present as a link(href) in source xml

I have the below code in source file

    <?xml version="1.0" encoding="utf-8"?>
    <?dx form=DxMapR4?>
    <!DOCTYPE map PUBLIC "-//OASIS//DTD DITA Map//EN" "Map.dtd"[]>
    <map id="DocID027853" rev="1" title="AN4696" ditaarch:DITAArchVersion="1.2"
      domains="(topic delay-d)                          (map mapgroup-d)                           (topic indexing-d)                          (map glossref-d)                          (topic hi-d)                           (topic ut-d)                           (topic hazard-d)                          (topic abbrev-d)                          (topic pr-d)                           (topic sw-d)                          (topic ui-d)                         "
      class="- map/map " xmlns:ditaarch="http://dita.oasis-open.org/architecture/2005/">
      <data name="DocType" value="Application note" class="- topic/data "/>
      <data name="AuthorName" value="Laura Vanzago" class="- topic/data "/>
      <topicref type="reference" locktitle="yes" navtitle="@NA" toc="no" class="- map/topicref "
        href="DocID027853_AN4696_short_description.dita"/>
topicref navtitle="SPWF01Sx power-up" class="- map/topicref "
    href="DocID027853_AN4696_6_SPWF01Sxxx_power_up.dita"/>
  <topicref navtitle="Glossary" class="- map/topicref " href="DocID027853_AN4696_7_Glossary.dita"/>
  <topicref navtitle="References" class="- map/topicref "
    href="DocID027853_AN4696_8_References.dita"/>
    <map/>

Now I want to parse the xml file present in first topicrefi.e."DocID027853_AN4696_short_description.dita".

Inside this file there is a title tag whose value I want to copy in my initial source xml. How can I do that? Is it possible using xslt to parse this other xml and copy its data in my source xml?

Solution

You can use the document() function followed by the Xpath of the element you want to select, e.g. <xsl:value-of select="document(DocID027853_AN4696_short_description.dita)/thetag"/>.