Not indexed nested objects

Hi everyone,
I've just started using logstash + elasticsearch for storing logs.
I started exploring my data and I figured that nested objects were not indexed, thus I can not visualise them, and I even can not use them for conditions (this is most important).
There is my mapping

"events" : { "type" : "nested", "properties" : { "timestamp" : { "type" : "date" }, "category" : { "type" : "string", "index": "not_analyzed" }, "level" : { "type" : "string", "index": "not_analyzed" }, "message" : { "type" : "string", "index": "not_analyzed" } } }

What is wrong here ?
Am I right that kibana just makes queries to elastic and does not do any indexing of my data itself ?


See Kibana does not show nested fields for discover or visualization