Postman pre-request script to fix nested json

This will expand json from the example data file into the body of a Postman HTTP request using collection runner.

Data file example:

{"tag":
{"TaskPriority":"0",
"Event":"record",
"Attributes":"{\"name\":\"Bob\",\"department\":\"water\"}"}}

Pre-request script in http request:

var inputJSONdata = pm.iterationData.get("tag");
pm.variables.set("input_body",JSON.stringify(inputJSONdata));

body of http request (in raw mode):

{{input_body}}

See this post for reference.