Challenge Overview
When group have events in challengeFilter, call API with events instead groupId.
Please ref. swagger file: https://github.com/topcoder-platform/challenge-api/blob/4a480a0e7c435a6e3d431fdfa03960bf3ce91455/docs/swagger.yaml#L184-L191
example:
"challengeFilter": {
"events": ["tco21"]
},