Database
[{"cdrId":"61574b3e58fb1cae1494df2c","date":"2021-10-01T17:54:06.057Z","intentType":"FALLBACK"},{"cdrId":"61574b3e58fb1cae1494df2c","date":"2021-10-01T17:54:06.057Z","intentType":"FAQ"},{"cdrId":"61570b37522aba5e2f205356","date":"2021-10-01T13:20:55.601Z","intentType":"TRANS/DISAM"},{"cdrId":"61570b37522aba5e2f205356","date":"2021-10-01T13:20:55.601Z","intentType":"FAQ"}]
Query
db.collection.aggregate([{$group:{_id:null,data:{$push:"$$ROOT"}}},{$unwind:{path:"$data",includeArrayIndex:"index"}},{$replaceRoot:{newRoot:{$mergeObjects:[{index:"$index"},"$data"]}}},])