Use proper JSON Path when updating nested JSON fields

[sumitshatwara]

Considering two scenarios below (consider the below variables as nested fields in JSON stored inside the address field):

1. variable name: city, updated path: $.address.city, it works fine
2. variable name: my_city, updated path: $.address.my.city, it failed as updated path should be: $.address.my_city (underscore was replaced by a dot)