How to Control Budget in Detail of Main Account

Dear All AX Experts,

I need your help, what do you think that my client want to control budget from a detail of Main Account, here the example :

My client want to control the detail of Account 520001 (Marketing Expense) that inside of Account 520001 (Marketing expense) there are banner expense, booth expense, advertising expense, etc. But there are no account of banner expense, booth expense, advertising expense, etc.

here the case :

My client want to control the detail of Main Account like banner expense, booth expense, advertising expense, etc. But my client doesn't like to add new account for that detail and my client doesn't like to add new financial dimension.

what do you think about this case? i need your opinions or solution for this case,

Thanks,

Christoper