elasticsearch query to filter by a max value within a unique group of items and apply result of query to aggregation counts

Question

Trying to get results for an elasticsearch query that are filtered by a max priority value based on a unique group id.

The difference is that my query already has aggregations and I want to limit the aggregation counts to prune them based on the max priority value within each unique group. I want to do this by adding the group/priority filter to the query filter.

The group value is, for example, ABC123.
So in my sample data below I have 2 items in 2 groups. My query then filters by product (GreatProduct) and language (English) and gets aggregations based on Color.
Currently I get 4 results back and an aggregation count of 4 based on color of Red.
So applying the unique group and max priority to the filter, I would expect to get back 2 items, one for each unique group with each item having a priority of 2 (max value).

My current solution is based on this post - How to make an elasticsearch query that filters on the maximum value of a field?. But the above solution, applies the max value/unique field, to the aggregations whereas I would like to apply this to the filter and have the aggregation counts reflect the filtering by max value/unique field.

Sample mapping:

{
   "myindex-2016.07.07": {
      "mappings": {
         "myindex": {
            "properties": {
               "title_en": {
                  "type": "string",
                  "store": true,
                  "analyzer": "english"
               },
               "description_en": {
                  "type": "string",
                  "store": true,
                  "analyzer": "english"
               },
               "id": {
                  "type": "long",
                  "store": true,
                  "include_in_all": false
               },
               "group": {
                  "type": "string",
                  "index": "not_analyzed",
                  "store": true,
                  "include_in_all": false
               },
               "priority_value": {
                  "type": "long",
                  "store": true,
                  "include_in_all": false
               },
               "product": {
                  "type": "string",
                  "index": "not_analyzed",
                  "store": true,
                  "include_in_all": false
               },
                  "language": {
              "type": "string",
              "index": "not_analyzed",
              "store": true,
              "include_in_all": false
           },
           "color": {
              "type": "string",
              "index": "not_analyzed",
              "store": true,
              "include_in_all": false
           }
            }
         }
      }
   }
}

Sample data:

  # first two items have same group id of "ABC123"
  curl -XPOST localhost:9200/myindex/myitem -d '{
    "id": 1,
    "title_en": "Title1",
    "desc_en": "Desc1",
    "group": "ABC123"
    "priority_value": 2
    "lang": "English"
    "product": "GreatProduct" 
    "color": "Red" 
  }'

  curl -XPOST localhost:9200/myindex/myitem -d '{
    "id": 2,
    "title_en": "Title2",
    "desc_en": "Desc2",
    "group": "ABC123"
    "priority_value": 1
    "lang": "English"
    "product": "GreatProduct" 
    "color": "Red" 
  }'

  # next two items have same group id of "XYZ789"
  curl -XPOST localhost:9200/myindex/myitem -d '{
    "id": 3,
    "title_en": "Title3",
    "desc_en": "Desc3",
    "group": "XYZ789"
    "priority_value": 1
    "lang": "English"
    "product": "GreatProduct" 
    "color": "Red" 
  }'

  curl -XPOST localhost:9200/myindex/myitem -d '{
    "id": 4,
    "title_en": "Title4",
    "desc_en": "Desc4",
    "group": "XYZ789"
    "priority_value": 2
    "lang": "English"
    "product": "GreatProduct" 
    "color": "Red" 
  }'