Elasticsearch term facet not showing negative terms
The negative sign is a special character in Lucene (and ElasticSearch).
While indexing and searching you need to escape it.
Try adding a \ before the - character in your index, that should bring it up in the facet as well.
Got the answer from Elasticsearch Google Group. Need to update the mapping of the field
Possible Solution:
Update the mapping and use
"index":"analyzed","analyzer" : "keyword"
or
"index": "not_analyzed"