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db.collection.aggregate([{"$group":{"_id":{region:"$region",year:"$year",week_number:"$week_number",location:"$location"},"v":{"$addToSet":"$$ROOT"}}},{$group:{_id:{region:"$_id.region",year:"$_id.year",week_number:"$_id.week_number"},v:{"$addToSet":{k:"$_id.location",v:"$v"}}}},{"$addFields":{"v":{"$arrayToObject":"$v"}}},{$group:{_id:{region:"$_id.region",year:"$_id.year"},v:{"$addToSet":{k:{"$toString":"$_id.week_number"},v:"$v"}}}},{"$addFields":{"v":{"$arrayToObject":"$v"}}},{$group:{_id:{region:"$_id.region"},v:{"$addToSet":{k:{"$toString":"$_id.year"},v:"$v"}}}},{"$addFields":{"v":{"$arrayToObject":"$v"}}},{$group:{_id:null,v:{"$addToSet":{k:"$_id.region",v:"$v"}}}},{"$addFields":{"v":{"$arrayToObject":"$v"}}},{"$replaceRoot":{"newRoot":"$v"}}])