How to aggregate sub buckets of each bucket on nested documents - elasticsearch

Question

Full sample code:
https://gist.github.com/anonymous/329eaaf5654096c529da
I have a simple, standard product/options mapping like this for a standard ecommerce site:
"mappings": {
"product": {
"properties" : {
"name":
{
"type": "string",
"fields": {
"raw": { "type": "string", "analyzer": "lowercase" }
},
"analyzer": "default"
},
"options" : {
"type": "nested",
"properties": {
"id": {"type": "integer"},
"name": {"type": "string"},
"values": {"type": "nested"}
}
},
"price":{"type": "integer"},
"createdAt": {
"type": "date",
"format": "basic_date_time"
}
}
}
}
Please note that 1 product has multiple options, and each option can have multiple values (ie.: a Shirt with option Color including blue, red; and option Size including M, XL)
Currently, after the query to search for products using multiple conditions, I aggregate the result to get a list of all options and options values in the result set:
"aggregations": {
"options": {
"nested": {
"path": "options"
},
"aggs": {
"options_ids": {
"terms": {
"field": "id"
}
},
"aggs": {
"nested": {
"path": "options.values"
},
"aggs": {
"options_values_ids": {
"terms": {
"field": "options.values.id"
}
}
}
}
}
}
}
All work well except I get something like this
"aggregations": {
"options": {
"doc_count": 4,
"options_ids": {
"buckets": [
{
"key": 1,
"doc_count": 2
},
{
"key": 2,
"doc_count": 2
}
]
},
"aggs": {
"doc_count": 7,
"options_values_ids": {
"buckets": [
{
"key": 1,
"doc_count": 2
},
{
"key": 5,
"doc_count": 2
},
{
"key": 2,
"doc_count": 1
},
{
"key": 3,
"doc_count": 1
},
{
"key": 6,
"doc_count": 1
}
]
}
}
}
}
As you can see, there is no way for me to know which option values belong to which options from the result. It will be much better if the available options values can be listed under each option. Is that possible at all?

Answer 1

You would need to nest your aggregations:
"aggregations": {
"options" : {
"aggs" : {
"options_ids" : {
"aggs" : {
"aggs" : {
"options_values_ids" : {
"terms" : {
"field" : "options.values.id"
}
}
},
"nested" : {
"path" : "options.values"
}
},
"terms" : {
"field" : "id"
}
}
},
"nested" : {
"path" : "options"
}
}
}