Hi Chris,
in general the question is: why would you change your data, when it gets visualized?
I would shape the data in the Splunk-search and try to get away with it. 🙂
If you really want to the JS-path I would check out this Tutorial:
https://docs.splunk.com/Documentation/SplunkCloud/8.0.0/AdvancedDev/CustomVizTutorial
It will also tell you how to import JS-modules (like Highcharts used in your fiddle) and in the examples visualization_source.js you can aswell see how data is processed before it gets fed to the visual. So for which ever transformation on the data you need, it could be done in the formatData. In the updateView function, you could then feed the data to a Highcharts.chart().
... View more