Database
[{songId:1,title:"My Anaconda Dont",details:{artist:"Doesnt Matter",album:"Who Cares",releaseYear:1888}},{songId:2,title:"My Bananaa Dont",details:{artist:"It Does",album:"I do care",releaseYear:1899}}]
Query
db.collection.aggregate([{$addFields:{artist:"$details.artist"}},{$project:{songId:1,title:1,artist:1,details:{album:1,releaseYear:1}}}])