[{"bookingId":"NW111","status":"SUCCESS","sent":false},{"bookingId":"NW111","status":"SUCCESS","sent":false},{"bookingId":"NW115","status":"SUCCESS","sent":false},{"bookingId":"NW115","status":"SUCCESS","sent":false},{"bookingId":"NW115","status":"SUCCESS","sent":false},{"bookingId":"NW111","status":"SUCCESS","sent":false},{"bookingId":"NW111","status":"PROCESSING","sent":false},{"bookingId":"NW115","status":"SUCCESS","sent":false},{"bookingId":"NW115","status":"ERROR","sent":false},{"bookingId":"NW115","status":"SUCCESS","sent":false}]

db.collection.aggregate([{$match:{sent:false}},{$group:{_id:"$bookingId",status:{$addToSet:"$status"}}},{$facet:{success:[{$match:{status:{$nin:["ERROR"]}}},{$match:{status:{$in:["SUCCESS"]}}},{$project:{success:"$_id",_id:0}}],error:[{$match:{status:{$in:["ERROR"]}}},{$project:{error:"$_id",_id:0}}]}},{$project:{concat:{"$concatArrays":["$error","$success"]}}},{$unwind:"$concat"},{$group:{_id:null,successBookingIds:{$push:"$concat.success"},errorBookingIds:{$push:"$concat.error"}}}])