I want to achieve something similar to AdWords UI's
Campaign -> Ad extensions -> Callout extensions -> Ad group extensions where a table of ad groups and their extensions are displayed.
Therefore, I need to get all the ad groups with extensions in an API call. What's the most efficient way to do this?
AdGroupExtensionSettingService has no campaign id selector.
Must I first get all the ad group ids and use those as the selector? This would require 2 separate calls one after the other which means it takes much longer to load.