[{"_id":"1234","NodesKey":"-14","NodesValue":{"_t":"DL","Key":"-14","Edges":[{"TargetNode":"-5"}],"Title":"Lookup","Text":"Data Lookup","ConnectionString":"Server=LOCALSERVER;Database=DataCache;User=sa;Password=1234;","TableName":"Customers","FieldMaps":[{"ID":2,"Column":"Name"},{"ID":1,"Column":"Number"}]}}]

db.collection.update({},[{"$set":{"NodesValue.ConnectionString":{"$replaceOne":{"input":"$NodesValue.ConnectionString","find":"Server=LOCALSERVER","replacement":"Server=NEWSERVER"}}}}])