Get a value in a nested object using Deluge

Get a value in a nested object using Deluge

My Question is: How can I write a Deluge function to look up a NESTED JSON value?

I want to find a record in say the Contacts Module, where the "Modified by" id ="29383XXXXXXXXXXXXXX".

{  
   "Modified_By":{  
      "name":"Ben",
      "id":"29383XXXXXXXXXXXXXX"
   },

I would really appreciate it if someone can help me.