[{"id":"asdfasdfasdf","shipDate":"2021-04-02","packages":[{"id":"adfasdfasdfasdf","contents":[{"product":{"id":1},"quantity":10},{"product":{"id":2},"quantity":10}]}]},{"id":"asdfasdfasdf","shipDate":"2021-04-02","packages":[{"id":"adfasdfasdfasdf","contents":[{"product":{"id":1},"quantity":10},{"product":{"id":2},"quantity":10}]}]}]

db.collection.aggregate([{"$match":{"shipDate":"2021-04-02","packages.contents.product.id":1}},{$unwind:"$packages"},{$unwind:"$packages.contents"},{"$match":{"packages.contents.product.id":1}},{"$group":{"_id":null,"total":{"$sum":"$packages.contents.quantity"}}}])