@prashanthpatil Do you need to simply validate that each of ST1 and ST2 have the mealCodes object in the response or do you need to validate the content in those objects?
You could do come sort of JSON validation like this …
pm.test("Validate Response Body Is Correct", function () {
var jsonData = pm.response.json();
pm.expect(jsonData.ABC.B.ST2.meals.mealCodes()).to.include("H");
pm.expect(jsonData.ABC.B.ST1.meals.mealCodes()).to.include("H");
});