How do I add fields on Reporting API Custom viewTemplate?

Follow these steps:

1. Create a custom viewTemplate.
2. Patch the custom viewTemplate by calling this API endpoint:
   
   POST /procurement-reporting-view/v2/prod/viewTemplates/nameofCustomViewTemplate/patch?realm=RealmName
   
   On the body part, specify: (note the real field example mixed in the code)
   
   {
   "selectAttributes": [
   "Attributes1",
   "Attributes2",
   "Attributes3",
   "cus_Attributes1",
   "cus_Attributes2",
   "StartDate",
   "UniqueId"
   ],
   "filterExpressions": [
   {
   "name": "FilterName",
   "field": "filterExpression1",
   "op": ">=",
   "defaultValue": "YYYY-MM-DDTHH:MI:SSZ"
   },
   {
   "name": "createdDateTo",
   "field": "TimeCreated",
   "op": "<=",
   "defaultValue": "2019-05-31T00:00:00Z"
   },
   {
   "name": "StatusInList",
   "field": "StatusString",
   "op": "IN",
   "defaultValue": [
   "Submitted"
   ]
   }
   ]
   }

1. Only the custom viewTemplate can be modified/patched. The system viewTemplate cannot be modified.
2. Invoke the GET /metadata API end point to bring back the available Select Fields and Filter Expressions. SAP Note 3635403 provides you further guidance on how to explore the metadata endpoint effectively.
3. Notice that on custom view, duplicate fields are not allowed.

• SAP Note 3635403 - OpenAPI: Need help checking the feasibility of extracting certain fields Ariba's Reporting APIs

Core Procurement > Procurement REST APIs > Operational Reporting API
SAP Ariba Analysis Reporting > Analytical Reporting - REST API
Strategic Sourcing > Strategic Sourcing - REST API > Strategic Sourcing - Operational Reporting API