Hi Rob,
Thanks for posting. The only way to do this currently is through filters, and it wouldn't be exactly what you're looking for as a filter wouldn't dynamically display the 'top counts'. Rather, it filters a specified array of values.
To do this, you'd have to setup a filter so that the chart only displays, say 'counts greater than 1.8' or 'between a range of 1.8 - 5'.
In the example below, I have roughly 10 classifications but only 5 of them are displayed in the chart after applying the filter:
What is your specific use case for having the top counts to be displayed dynamically in a chart card, Rob?