[{_id:1,name:"Colors company",shops:[{shopID:1,income:0},{shopID:2,income:0},{shopID:3,income:0}]}]

db.collection.update({},[{$addFields:{shops:{"$map":{"input":"$shops","as":"s","in":{"$cond":{"if":{$eq:["$$s.shopID",2]},"then":{$mergeObjects:["$$s",{income:{$sum:["$$s.income",200]}}]},"else":"$$s"}}}}}}])