Are you trying to get the latest artifact for a single application or just a list of the latest artifacts for all applications that are currently stored on your Nexus?
If just a single application then you could use the find files/ folders action and point it at the directory for the application (%NolioServerRepository%\sonatype-work\nexus\storage\nolio\<application ID>) and then sort descending by last modified. If you are looking for all of the latest artifacts for all applications then it may be a bit more complicated:
1. point to the %NolioServerRepository%\sonatype-work\nexus\storage\nolio folder and write the contents to a string array
2. set up a FOREACH loop on the string array and output to a component parameter using the iteration element, say <app-id>
3. Use the find files or folders action on this path: %NolioServerRepository%\sonatype-work\nexus\storage\nolio\<app-id> and sort descending by last modified.
That's just a suggestion and feel free to reach out to me by email if I'm missing the mark. We use an external Nexus repository in our environment so I am pretty familiar with querying against it for various pieces of info.