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db.collection.aggregate([{"$unwind":"$slots"},{"$match":{"slots._id":"5f8970f19e6afb628a2edd07_5f8970f18b3aa"}},{"$project":{_id:0,price:"$slots.price",duration:"$slots.duration",created_at:"$slots.created_at",updated_at:"$slots.updated_at",_id:"$slots._id",available_quantity:"$slots.available_quantity",quantity:"$slots.quantity"}}])