Is there anyway to create an index from another index but only taking certain fields, not all? The new index would have a new ID as well and include a new alias. I was looking at the reindex API and the clone API as maybe a possible solution however not sure if this is able to accomplish this. Another possible solution could be somehow making text file from the index and then transforming that file as needed to then reingest into the new index, however, this process seems to be the longest in terms of time as the original index may have more than 20 million records/documents.
An example of a document in the original document would be:
The new index would then have :
The example is only for one record but it would be for the whole index, all documents in that index.