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db.collection.aggregate([{$project:{data:{$map:{input:{$objectToArray:"$report"},in:"$$this.v"}}}},{$unwind:"$data"},{$project:{data:{$map:{input:{$objectToArray:"$data"},in:"$$this.v"}}}},{$unwind:"$data"},{$project:{data:{$map:{input:{$objectToArray:"$data"},in:"$$this.v"}}}},{$unwind:"$data"},{$unwind:"$data.DATA"},{$replaceRoot:{newRoot:"$data.DATA"}}])