Hi,

drill down is going to be little tricky, I found a JSFiddle for drilldown highcharts, it needs drilldown.js, once I associate that it throws error on other required chart core components.

Other option is, 

1. create a variable of type DataPoint List
2. onDataFetch assign this variable, this should display the initial chart
3. make the clickable for chart to true, assign the local variable for source and create a onclick action
4. the new onclick event should have the datapoint that user clicked, which you can use to get the data and update the local variable.
5. You will have to have another button to go back in case user has drilled down.

Regards.