ElasticSearch: Get distinct field values from multi_match - elasticsearch

Question

My Query with multiple multi_matches looks like follows:
"query": {
"bool": {
"should" : [
{"multi_match" : {
"query": "test",
"fields": ["field1^15", "field2^8"],
"tie_breaker": 0.2,
"minimum_should_match": "50%"
}},
{"multi_match" : {
"query": "test2",
"fields": ["field1^15", "field2^8"],
"tie_breaker": 0.2,
"minimum_should_match": "50%"
}
}
]
}
}
I want to get all distinct field1 values which match the query. How can I realize that?
EDIT:
Mapping:
"field1": {
"type": "text",
"fields": {
"keyword": {
"type": "keyword",
"ignore_above": 256
}
},
"analyzer": "nGram_analyzer"
}
This is what I tried so far (I still get multiple identical field1 values):
"query": {
"bool": {
"should" : [
{"multi_match" : {
"query": "test",
"fields": ["field1^15", "field2^8"],
"tie_breaker": 0.2,
"minimum_should_match": "50%"
}},
{"multi_match" : {
"query": "test2",
"fields": ["field1^15", "field2^8"],
"tie_breaker": 0.2,
"minimum_should_match": "50%"
}
}
]
}
},
"aggs": {
"field1": {
"terms": {
"field": "field1.keyword",
"size": 100 //1
}
}
}
UPDATE:
The query
GET /test/test/_search
{
"_source": ["field1"],
"size": 10000,
"query": {
"multi_match" : {
"query": "test",
"fields": ["field1^15", "field2^8"],
"tie_breaker": 0.2,
"minimum_should_match": "50%"
}
},
"aggs": {
"field1": {
"terms": {
"field": "field1.keyword",
"size": 1
}
}
}
}
results in
{
"took": 4,
"timed_out": false,
"_shards": {
"total": 10,
"successful": 10,
"skipped": 0,
"failed": 0
},
"hits": {
"total": 35,
"max_score": 110.26815,
"hits": [
{
"_index": "test",
"_type": "test",
"_id": "AVzz99c4X4ZbfhscNES7",
"_score": 110.26815,
"_source": {
"field1": "test-hier"
}
},
{
"_index": "test",
"_type": "test",
"_id": "AVzz8JWGX4ZbfhscMwe_",
"_score": 107.45808,
"_source": {
"field1": "test-hier"
}
},
{
"_index": "test",
"_type": "test",
"_id": "AVzz8JWGX4ZbfhscMwe_",
"_score": 107.45808,
"_source": {
"field1": "test-da"
}
},
...
So actually there should only be one "test-hier".

Answer 1

You can add a terms aggregation on the field1.keyword field and you'll get all distinct values (you can change size to any other value that better matches the cardinality of your field):
{
"size": 0,
"query": {...},
"aggs": {
"field1": {
"terms": {
"field": "field1.keyword",
"size": 100
},
"aggs": {
"single_hit": {
"top_hits": {
"size": 1
}
}
}
}
}
}