[{"_id":"2023-04-08","dailyNotes":[{"therapyDiscipline":"PT","individual":[60,45,30,75,55]},{"therapyDiscipline":"YT","individual":[2,4]}]}]

db.collection.aggregate([{$project:{_id:1,dailyNotes:{$map:{input:"$dailyNotes",in:{individual:{$sum:"$$this.individual"}}}}}}])