Hello Chirag,
You may use the AdGroup Performance Report which will return stats based on the AdGroup, with one row per AdGroup. You can then filter based on the Campaign ID to pull the campaign level metrics. Please find below the sample report query:
SELECT AdGroupId, AdGroupName, CampaignId, Clicks, Conversions FROM ADGROUP_PERFORMANCE_REPORT WHERE CampaignId IN ["123456789"]
If this is not what you're looking for, could you share us a screenshot of the UI, so I can take a look?
Thanks,
Bharani, AdWords API Team