Are you set on doing Business after?
Some universities offer double degrees, meaning that you can study both degrees concurrently. So, for example, you could study a Bachelor of Arts/Bachelor of Business. This doesn't really make your time at uni harder as such - just a bit longer. But it's quicker doing it this way (as a double degree) than studying a full Bachelor of Arts, and then a full Bachelor of Business.
Another option is to study Arts and concurrently study another Business qualification - but not necessarily a Bachelor (a Diploma, for example). The suitability of this probably depends on what you want to do with your business qualification(s), and what you want to do after university.
Theoretically, you could study a Bachelor of Arts, finish, and then start a Bachelor of Business. I don't see many advantages of this over the double degree.
And if you get through the Bachelor of Arts and then still want to study Business, you could try a "higher" qualification - but again, this is very dependent. EDIT: As Brenden says above, probably an MBA.
What do you want to do after uni? Do any of those options seem suitable?