feature request: filter / split on nested json data (or request documentation if it's already there)

[c0b]

I'm not sure if plywood has nested json data support already, or not? from http://imply.io/docs/latest/tutorial-batch it says not

Let's use a small pageviews dataset as an example. Druid supports TSV, CSV, and JSON out of the box. Note that nested JSON objects are not supported, so if you do use JSON, you should provide a file containing flattened objects.

but when I give it nested json data, with Dataset.fromJS(nested_jsondata) it says this nested bidderTiming is filterable and splitable, however I don't know how to write the plywood expresssion