anchor.diff:  Multi-level nesting is automatically supported, and detected, resulting in an
   inner nested query to automatically match the relevant nesting level, rather
   than root, if it exists within another nested query.
  +
  +See <<multi-level-nested-query-ex>> for an example.
   --
   
   `score_mode`::
  
positive.code: ----
  GET /my_index/_search
  {
      "query": {
          "nested" : {
              "path" : "obj1",
              "query" : {
  
negative.code: 
  You can use this parameter to query multiple indices that may not contain the
  field `path`.
  --
  
  [[nested-query-notes]]
  ==== Notes
  
  [[multi-level-nested-query-ex]]
  ===== Multi-level nested queries
  
  To see how multi-level nested queries work,
  first you need an index that has nested fields.
  The following request defines mappings for the `drivers` index
  with nested `make` and `model` fields.
  
  [source,console]
  ----
  PUT /drivers
  {
      "mappings" : {
          "properties" : {
              "driver" : {
                  "type" : "nested",
                  "properties" : {
                      "last_name" : {
                          "type" : "text"
                      },
                      "vehicle" : {
                          "type" : "nested",
                          "properties" : {
                              "make" : {
                                  "type" : "text"
                              },
                              "model" : {
                                  "type" : "text"
                              }
                          }
                      }
                  }
              }
          }
      }
  }
  ----
  
  Next, index some documents to the `drivers` index.
  
  [source,console]
  ----
  PUT /drivers/_doc/1
  {
    "driver" : {
          "last_name" : "McQueen",
          "vehicle" : [
              {
                  "make" : "Powell Motors",
                  "model" : "Canyonero"
              },
              {
                  "make" : "Miller-Meteor",
                  "model" : "Ecto-1"
              }
          ]
      }
  }
  
  PUT /drivers/_doc/2?refresh
  {
    "driver" : {
          "last_name" : "Hudson",
          "vehicle" : [
              {
                  "make" : "Mifune",
                  "model" : "Mach Five"
              },
              {
                  "make" : "Miller-Meteor",
                  "model" : "Ecto-1"
              }
          ]
      }
  }
  ----
  // TEST[continued]
  
  You can now use a multi-level nested query
  to match documents based on the `make` and `model` fields.
  
  [source,console]
  ----
  GET /drivers/_search
  {
      "query" : {
          "nested" : {
              "path" : "driver",
              "query" : {
                  "nested" : {
                      "path" :  "driver.vehicle",
                      "query" :  {
                          "bool" : {
                              "must" : [
                                  { "match" : { "driver.vehicle.make" : "Powell Motors" } },
                                  { "match" : { "driver.vehicle.model" : "Canyonero" } }
                              ]
                          }
                      }
                  }
              }
          }
      }
  }
  ----
  // TEST[continued]
  
  The search request returns the following response:
  
  [source,console-result]
  ----
  {
    "took" : 5,
    "timed_out" : false,
    "_shards" : {
      "total" : 1,
      "successful" : 1,
      "skipped" : 0,
      "failed" : 0
    },
    "hits" : {
      "total" : {
        "value" : 1,
        "relation" : "eq"
      },
      "max_score" : 3.7349272,
      "hits" : [
        {
          "_index" : "drivers",
          "_id" : "1",
          "_score" : 3.7349272,
          "_source" : {
            "driver" : {
              "last_name" : "McQueen",
              "vehicle" : [
                {
                  "make" : "Powell Motors",
                  "model" : "Canyonero"
                },
                {
                  "make" : "Miller-Meteor",
                  "model" : "Ecto-1"
                }
              ]
            }
          }
        }
      ]
    }
  }
  ----
  // TESTRESPONSE[s/"took" : 5/"took": $body.took/]
  