@Brotfahrer as @Daniel_Weikert has said an example might help.
The hub repository of @mw seems to contain various examples that deal with the unwrapping of XML and JSON files into tables. Maybe you try to further explore there also:
https://hub.knime.com/mw/spaces/Public/latest/Knime%20Forum%20Support/
Then with an idea by @Andrew_Steel there was an example where an asterisk was used to introduce a dynamic element into an XPath: