[{"data":[{"type":"abc","price":25000,"inventory":15},{"type":"def","price":8000,"inventory":150}]}]

db.collection.aggregate([{$unwind:"$data"},{$project:{data:["$data.type",{price:"$data.price",inventory:"$data.inventory"}],}},{$group:{_id:"$_id",doc:{$push:"$$ROOT"}}},{$replaceRoot:{newRoot:{$arrayToObject:"$doc.data"}}}])