Hi Rj,
As per your 1st Payload
I have tried to stringify and parse the payload using fix script so that you can have an idea
var payload = {
"TaskNum": "1",
"TaskName": "ABC",
"Link": "https://www.google.com/",
"Data1": {
"Type": "T1",
"Priority": 1,
"Date": "4-11-2022"
},
"Data2": {
"Type": "T2",
"Priority": 1,
"Date": "4-11-2022"
}
};
var grjson = JSON.stringify(payload);
gs.print('JSON :' +grjson);
var parser = JSON.parse(grjson);
gs.print("Parsed Task Num:" + parser.TaskNum);
gs.print("Parsed Task Name:" + parser.TaskName);
gs.print("Parsed Data1:" + parser.Data1.Type + "Priority :" +parser.Data1.Priority + "Date1" + parser.Data1.Date);
gs.print("Parsed Data2:" + parser.Data2.Type + "Priority :" +parser.Data2.Priority + "Date2" + parser.Data2.Date);
// Now coming to your queries , The second payload is showing as duplicate entry . I will attached the screenshot . You can have look. Please share sample payload . Not sure if you have share the exact payload.
If you are triggering through the integration . You can get the entire payload in the one variable.
something like
var jsonarr = [];
jsonarr.push(grjson);
gs.print('multirequest' +jsonarr ); // Try to validate once .
Question is how you will utilising in your requestbody . Sample script.
var r = new sn_ws.RESTMessageV2('Integration using SCripted Rest API', 'Update Incident'); // just a sample name
r.setStringParameterNoEscape('multirequest', jsonarr.toString());
// Similarly you can send the other attribute as well .
var response = r.execute();
var responseBody = response.getBody(); //get Response Body
var httpStatus = response.getStatusCode();
var getBody = r.getRequestBody();
NOTE: This is not the exact solution but just giving you the fair idea to get started . I will be sharing few links to you show that it can helpfull. 
Important Link: JSON Parsing - ServiceNow Community
Solved: Get values from an array in Json format - ServiceNow Community
