simplified_query.json

{
   "aggs": {
      "author": {
         "terms": {
            "field": "author_ids"
         }
      },
      "categories": {
         "terms": {
            "field": "category_ids",
            "size": 100
         }
      },
      "format": {
         "terms": {
            "field": "format"
         }
      },
      "audience": {
         "terms": {
            "field": "intended_audience"
         }
      },
      "language": {
         "terms": {
            "field": "language"
         }
      }
   },
   "explain": false,
   "fields": [
      "site_id"
   ],
   "from": 0,
   "query": {
      "filtered": {
         "filter": {
            "bool": {
               "must": [
                  {
                     "term": {
                        "site_ids": 1
                     }
                  },
                  {
                     "term": {
                        "category_ids": 1
                     }
                  }
               ]
            }
         },
         "query": {
            "function_score": {
               "functions": []
            }
         }
      }
   },
   "size": 30,
   "sort": [
      {
         "is_available": {
            "order": "desc"
         }
      },
      {
         "_score": {
            "order": "desc"
         }
      }
   ]
}