the document is saying as below but its not clear if and how the nested JSON will work
The following serializers are provided for Hive sink:
JSON: Handles UTF8 encoded Json (strict syntax) events and requires no configuration. Object names in the JSON are mapped directly to columns with the same name in the Hive table. Internally uses org.apache.hive.hcatalog.data.JsonSerDe but is independent of the Serde of the Hive table. This serializer requires HCatalog to be installed.
DELIMITED: Handles simple delimited textual events. Internally uses LazySimpleSerde but is independent of the Serde of the Hive table.