Hi,
The group_placement_view maps to the Placements menu on the left of the UI then to the WHERE ADS SHOWED tab. While there is currently no UI view of the detail_placement_view, this was previously found in the Display Network tab then to the inner Placements tab then clicking the See details->All menu in the old AdWords UI.
The field group_placement_target_url is given at the group_placement level, whereas the placement field is from the detail level.
Regards,
Anthony
Google Ads API Team

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