Add the option to control how grouped transactions are displayed in the Spending Breakdown on the Overview page, similar to the existing option on the Analyze page.

On the Analyze page, users can click the gear icon and, under "Count grouped transactions," choose whether grouped transactions are counted "Individually" (using their original categories) or "In group" (using the group's category).

Implementing the same setting in the Spending Breakdown would allow users to choose whether grouped transactions and their amounts appear under their original categories or under the grouped transaction's category.