Dynamically building ChartJS objects using passed variables

Hi, I have built several ChartJS objects using the https://docs.mendix.com/howto/extendability/visualize-data-using-the-chartsjs-module documentation. Currently these charts' datasource use a microflow where I create variables to statically populate several values (e.g.: Resources, States) which the microflow uses to iterate and filter through (Usage) records. How do I dynamically select some values on the page in a drop-down (e.g. a handful of States) and pass them to the microflow, so that I can assign these microflow variables with these passed values? Any hints are will appreciated, Guislain