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db.collection.aggregate([{$group:{_id:{year:"$year",week_number:"$week_number"},ids:{$push:"$_id"}}},{$sort:{"_id.year":-1,"_id.week_number":-1}},{$limit:1},{"$lookup":{"from":"collection","localField":"ids","foreignField":"_id","as":"docs"}},{"$unwind":"$docs"},{"$replaceRoot":{"newRoot":"$docs"}}])