Google Ads accounts have three levels.To change their budget,at which level would an advertiser make their change?

Advertisers can set budgets at both the account level and the campaign level. An account-level budget applies across all campaigns within that account, providing an overall spending limit. Campaign-level budgets, which are more common, allow advertisers to allocate specific amounts to individual campaigns, offering granular control over spending for different marketing objectives or product lines. While ad groups are used for organizing keywords and ads, and ads are the creative content, neither of these levels has budget-setting capabilities. Therefore, the flexibility to manage budgets exists at either the account or campaign level.