[{id:1,number:10},{id:2,number:11},{id:3,number:12}]

db.collection.aggregate([{"$group":{"_id":null,"number":{"$push":"$$ROOT"},"other_numbers":{"$push":"$$ROOT"}}},{"$unwind":"$number"},{"$set":{"other_numbers":{"$filter":{"input":"$other_numbers.number","as":"i","cond":{"$ne":["$$i","$number.number"]}}},"number":"$number.number","_id":"$number.id"}}])