[{userName:"user-name",userId:"user-id",playlistArray:[{playlistName:"playlist1",playlistSongs:[{title:"",duration:0,uri:""},{title:"",duration:0,uri:""},{title:"",duration:0,uri:""},],},{playlistName:"playlist2",playlistSongs:[{title:"",duration:0,uri:""},{title:"",duration:0,uri:""},{title:"",duration:0,uri:""},],},],}]

db.collection.update({},{$addToSet:{"playlistArray.$[pl].playlistSongs":{$each:[{title:"1",duration:123,uri:"a"},{title:"2",duration:456,uri:"b"},{title:"3",duration:789,uri:"c"},]},},},{arrayFilters:[{"pl.playlistName":"playlist2",},],})