You're in law school presumably so that you can become a lawyer.
So by applying to b-school while you're still in law school, it suggests that you have no intention of practicing law. So it begs the question: why are you in law school?
And if it's really as a "back up plan" - then it also begs the question: why are you spending 3 years on a backup plan rather than focusing your efforts on going after your main plan? And to add to it, you have a business undergrad degree on top of that. And very limited work experience. No adcom is going to buy whatever story you'll try to spin.
Again, if you're really interested in a career in business, you have to seriously ask yourself why you're in law school at this point.
It's sort of like expecting to attract the girl you really want while still being in a relationship with your current girlfriend you're not really interested in anyways, but willing to settle for.
You really have two choices at this point:
(1) Finish up law school, and get a job (either pass the bar and practice law, or do something else).
(2) Drop out of law school now, and find a job -- you have a business undergrad degree, you're probably a pretty smart guy, so you're still in the running for a lot of entry-level type jobs out there in the business/corporate world (be it consulting, marketing, finance, etc.) - it may not be McKinsey or Goldman, but with patience and hustle you'll find a good job. If you really don't like the law, then losing one year to gain two is certainly better than losing all three years.
Either way, it won't involve getting an MBA for a while. And yes, I understand that either choice isn't going to be easy, but it's certainly more feasible and sensible than going for yet another degree at this point when you've sort of started your current program.
Or even if you did get an MBA, what makes you think that you'll all of a sudden be more employable with your resume (a biz undergrad degree, a law degree and an MBA and next to no work experience?). What makes you think you'll be competing for the same kinds of jobs as your more experienced MBA classmates with 3-6 years of solid pre-MBA experience? If anything, you'll likely be going after the same jobs as you would now with a biz undergrad degree. Piling on one degree credential after another isn't going to make you more employable - it can in fact backfire and make you seem less prepared for the real world.
This may be tough medicine to swallow, but you're going to have to face the music sooner or later (pardon the string of cliches).