First thing, be sure that your xml file is included in the sources. By default, the maven scanner only includes pom.xml for xml files. You can do so, by using, for instance, the sonar.sources property.
Trying to reproduce your case, I placed a xml file in the src/main/resources and needed to setup my sources as following to catch it (don’t forget to force inclusion of the pom as well, or you will lose it):
Now, regarding your XML XPath rule, what node from the XML file are you trying to target?
I tried using directly your XPath rule //ATTRIBUTE[@tokenValue='lang'] against your example with a online XPath tester (https://www.freeformatter.com/xpath-tester.html) and the rule does not match any node!
However, I was able to raise two issues with the following expression: //title[@lang='eng'].
Thank you so much for your response. I managed to get it to work (prior to your response) by adding the path to the folder which contains the url like this on the (extended) xpath rule like this: **/*.xml
But i understand now that this can be done on the pom file as well, and thus be made generic for all rules.