gistfile1.json

{
   "size":"10",
   "query":{
      "query_string":{
         "default_operator":"and",
         "query":"test",
         "phrase_slop":1,
         "analyze_wildcard":true
      }
   },
   "sort":[
      "_score"
   ],
   "fields":[
      "conference_id",
      "chat.visitor.nick",
      "chat.operators.nick",
      "chat.messages.message"
   ],
   "filter":{
      "and":[
         {
            "exists":{
               "field":"chat.messages.message"
            }
         },
         {
            "exists":{
               "field":"chat.visitor.livechat_id"
            }
         }
      ]
   }
}

{
   "size":"10",
   "query":{
      "query_string":{
         "default_operator":"and",
         "query":"<test>",
         "phrase_slop":1,
         "analyze_wildcard":true
      }
   },
   "sort":[
      "_score"
   ],
   "fields":[
      "conference_id",
      "chat.visitor.nick",
      "chat.operators.nick",
      "chat.messages.message"
   ],
   "filter":{
      "and":[
         {
            "exists":{
               "field":"chat.messages.message"
            }
         },
         {
            "exists":{
               "field":"chat.visitor.livechat_id"
            }
         }
      ]
   }
}