What I specify a doc with a field other than '_id'?

[khalidnajm]

In the MLT query, in order to search by document, rather than terms, I know I can specify a document by its _id. I find tedious, because I have to search for the document within the index and then copy other it's _id to my MLT query. I would rather search by path.virtual, or something else that's easily-accessible.

Any advice?

GET doc_cat/_search
{
    "query": {
        "more_like_this" : {
            "fields" : ["content","file.content_type"],
            "like" :[
              {
                "_index" : "doc_cat",
                "_id" : "59ffedd643299d3fff1f43f2dd43fe3c"
              },
              {
                "_index" : "doc_cat",
                "_id" : "132c508aa6155c97206db951c4662987"
              }
              ]
        }
    }
}