[{"_id":ObjectId("636a6aa584d5f92f14f0c548"),"products":[{"quantity1":"10 grams","quantity2":"24 grams","user_id":"602cf72a3fcad3cc605b8d59"},{"quantity1":null,"quantity2":null,"user_id":"602cf72a3fcad3cc605b8d50"}]},{"_id":ObjectId("602e443bacdd4184511d6e29"),"products":[{"quantity1":null,"quantity2":null,"user_id":"602cf72a3fcad3cc605b8d59"},{"quantity1":null,"quantity2":null,"user_id":"602cf72a3fcad3cc605b8d59"},{"quantity1":null,"quantity2":null,"user_id":"602cf72a3fcad3cc605b8d59"}]},{"_id":ObjectId("60332242acdd4184511ed664"),"products":[{"quantity1":null,"quantity2":"null","user_id":"602cf72a3fcad3cc605b8d59"},{"quantity1":null,"quantity2":"null","user_id":"602cf72a3fcad3cc605b8d59"},{"user_id":"602cf72a3fcad3cc605b8d59"}]}]

db.collection.aggregate([{$match:{products:{$elemMatch:{quantity1:null,quantity2:null}}}},{"$set":{"_tmp.type_is_null":{"$map":{input:"$products",as:"product",in:{"q1_null":{$eq:["null",{$type:"$$product.quantity1"}]},"q2_null":{$eq:["null",{$type:"$$product.quantity1"}]}}}}}},{$set:{"_tmp.only_nulls":{$reduce:{input:"$_tmp.type_is_null",initialValue:true,in:{$and:["$$value","$$this.q1_null","$$this.q2_null"]}}}}},{$match:{"_tmp.only_nulls":true}}])