title: Not able to Parse Nested JSON in Logstash
body: <p>I have nested json to parse in logstash. My log looks like:</p>
  
  <pre><code>{
      "schema": {
          "type": "struct",
          "fields": [{
              "type": "string",
              "optional": false,
              "field": "event"
          }, {
              "type": "int16",
              "optional": false,
              "field": "partition"
          }, {
              "type": "string",
              "optional": false,
              "field": "key"
          }, {
              "type": "int64",
              "optional": false,
              "field": "cas"
          }, {
              "type": "int64",
              "optional": false,
              "field": "bySeqno"
          }, {
              "type": "int64",
              "optional": false,
              "field": "revSeqno"
          }, {
              "type": "int32",
              "optional": true,
              "field": "expiration"
          }, {
              "type": "int32",
              "optional": true,
              "field": "flags"
          }, {
              "type": "int32",
              "optional": true,
              "field": "lockTime"
          }, {
              "type": "string",
              "optional": true,
              "field": "content"
          }],
          "optional": false,
          "name": "com.couchbase.DcpMessage"
      },
      "payload": {
          "event": "mutation",
          "partition": 272,
          "key": "Logs::1295f07e-09c0-4a4c-bb2e-fc5240fb5232",
          "cas": 1503898266643070976,
          "bySeqno": 1,
          "revSeqno": 1,
          "expiration": 0,
          "flags": 0,
          "lockTime": 0,
          "content": "{\"_sync\":{\"rev\":\"1-ca7cfba46d5e2567a41092e579940748\",\"sequence\":698,\"recent_sequences\":[698],\"history\":{\"revs\":[\"1-ca7cfba46d5e2567a41092e579940748\"],\"parents\":[-1],\"channels\":[null]},\"time_saved\":\"2017-08-28T05:30:43.587693145Z\"},\"componentName\":\"Virgin Voyages\",\"componentVersion\":\"1.2.5\",\"corelationId\":\"1503897743127\",\"deviceinfo\":{\"id\":\"5c9142899222677d\",\"name\":\"samsung SM-G900M\",\"operatingSystem\":\"Android\",\"osVersion\":\"6.0.1\",\"type\":\"Phone\"},\"hostname\":\"samsung SM-G900M\",\"message\":null,\"messageCode\":\"INJECT\",\"messageDetail\":\"{\\\"informationType\\\":\\\"beaconDetails\\\",\\\"actionData\\\":[{\\\"beacon_id\\\":\\\"b9407f30-f5f8-466e-aff9-25556b57fe6d:19755:58997\\\",\\\"distance\\\":3.346020288426232},{\\\"beacon_id\\\":\\\"b9407f30-f5f8-466e-aff9-25556b57fe6d:20063:45814\\\",\\\"distance\\\":8.37788453900756},{\\\"beacon_id\\\":\\\"b9407f30-f5f8-466e-aff9-25556b57fe6d:24416:27026\\\",\\\"distance\\\":8.170533849237675},{\\\"beacon_id\\\":\\\"b9407f30-f5f8-466e-aff9-25556b57fe6d:38529:59955\\\",\\\"distance\\\":4.72251958192618},{\\\"beacon_id\\\":\\\"b9407f30-f5f8-466e-aff9-25556b57fe6d:40536:39585\\\",\\\"distance\\\":4.699073594284207},{\\\"beacon_id\\\":\\\"b9407f30-f5f8-466e-aff9-25556b57fe6d:40795:1374\\\",\\\"distance\\\":9.36269856965088},{\\\"beacon_id\\\":\\\"b9407f30-f5f8-466e-aff9-25556b57fe6d:42423:37145\\\",\\\"distance\\\":2.5632779653262023},{\\\"beacon_id\\\":\\\"b9407f30-f5f8-466e-aff9-25556b57fe6d:44572:21424\\\",\\\"distance\\\":5.1373696851890704},{\\\"beacon_id\\\":\\\"b9407f30-f5f8-466e-aff9-25556b57fe6d:51771:64898\\\",\\\"distance\\\":3.9813075660947947},{\\\"beacon_id\\\":\\\"b9407f30-f5f8-466e-aff9-25556b57fe6d:52163:7961\\\",\\\"distance\\\":6.976285634989775},{\\\"beacon_id\\\":\\\"b9407f30-f5f8-466e-aff9-25556b57fe6d:5569:23454\\\",\\\"distance\\\":5.350671148905375},{\\\"beacon_id\\\":\\\"b9407f30-f5f8-466e-aff9-25556b57fe6d:60383:48481\\\",\\\"distance\\\":5.1373696851890704},{\\\"beacon_id\\\":\\\"b9407f30-f5f8-466e-aff9-25556b57fe6d:6949:14480\\\",\\\"distance\\\":4.337792827947945},{\\\"beacon_id\\\":\\\"f7826da6-4fa2-4e98-8024-bc5b71e0893e:29949:42958\\\",\\\"distance\\\":3.6595317170226993},{\\\"beacon_id\\\":\\\"f7826da6-4fa2-4e98-8024-bc5b71e0893e:32521:11968\\\",\\\"distance\\\":5.0375909818338265}]}\",\"offset\":\"+05:30\",\"severity\":\"Debug\",\"stacktrace\":null,\"timestamp\":\"2017-08-28T10:52:23.126\",\"traceinfo\":{\"duration\":\"0\",\"loggingPoint\":null,\"methodTime\":\"2017-08-28T10:52:23.126\"},\"type\":\"log\",\"userinfo\":{\"appId\":null,\"deviceId\":null,\"id\":null,\"token\":null,\"type\":null}}"
      }
  }
  </code></pre>
  
  <p>When I am applying json filter as source => "message", my logs are parsed but in my payload.content field, there is another json, I want to parse it also. I tried json filter on source => "[message][payload][content]" but no success after that. It is not able to parse my nested json of payload.content field. Please guide me.</p>