This field allows to define a Java capturing groups to extract version information from the full artifact path. In a nutshell define a regex and define a part of a string as a group by surrounding it with ( ) brackets to define a group. The first outer group found is used to extract the version information. Following is an example for a Maven artifact with the regex .+/(\d+\.\d+(\.\d+((-CANDIDATE)?-SNAPSHOT)?)?)/.+.

Path Version
http://localhost:8081/maven-releases/org/example/test/1.0/test-1.0.jar 1.0
http://localhost:8081/maven-releases/org/example/test/1.0.5/test-1.0.5.jar 1.0.5
http://localhost:8081/maven-releases/org/example/test/1.0.5-CANDIDATE-SNAPSHOT/test-1.0.5-CANDIDATE-SNAPSHOT.jar 1.0.5-CANDIDATE-SNAPSHOT