[{"_id":ObjectId("611f0b9f9964fea718ccea5f"),"quotationNO":"Q-000001","note":"21-8-2021<->send to DC<->John<#>21-8-2021<->OK<->Bob"},{"_id":ObjectId("611f2afa9964fea718ccea9c"),"quotationNO":"Q-000002","note":"22-8-2021<->send to DC<->Bob"}]

db.collection.aggregate([{"$addFields":{"note":{"$split":["$note","<#>"]}}},{"$addFields":{"note":{"$map":{"input":"$note","as":"n","in":{$split:["$$n","<->"]}}}}},{"$addFields":{"note":{"$map":{"input":"$note","as":"n","in":{"data":{"$arrayElemAt":["$$n",0]},"message":{"$arrayElemAt":["$$n",1]},"user":{"$arrayElemAt":["$$n",2]}}}}}},{"$merge":{"into":"new_collection","on":"_id","whenMatched":"replace","whenNotMatched":"insert"}}])