Hi Markushg,   When you want to apply condition on any number of attributes based on a pattern match. Then you may consider using anyMatchingAttribute NiFi Function.   Here is the link to the documentation: https://nifi.apache.org/docs/nifi-docs/html/expression-language-guide.html#anyattribute   In your case, You may have to do something like as below: ${anyMatchingAttribute("syslog.structuredData*os"):equals('linux69')} ... View more