To have access to the full list of dimensions available for Amazon Ads, you can check in the Custom Reports
Account daily budget
Account id
Account marketplace id
Account name
Account sub type
Account type
Account valid payment method
Campaign
Campaign bidding strategy
Campaign budget type
Campaign creation date
Campaign daily budget
Campaign end date
Campaign id
Campaign placement
Campaign portfolio id
Campaign premium bid adjustment
Campaign serving status
Campaign start date
Campaign state
Campaign targeting type
Campaign type
Channel
Date
Device
Profile id
Timezone