2nd bachelors vs 2nd masters
Ask your employer. They're the ones funding you after all.

Having said that I strongly suspect they'll prefer a 2nd Masters as opposed to 2nd Bachelor's. Several reasons:


Masters degrees usually take a much shorter time to get.
You learn more in a Masters. Bachelor's degree are broader in the sense that you often have breadth requirements. You can't focus everything on your major. That doesn't apply to a Masters degree.
You learn more advanced things in a Masters degree. If you have a Masters in [topic], you are assumed to be qualified for jobs that require a Bachelor's in [topic]. The reverse doesn't hold.
Holding two Bachelor's degrees is pretty unusual. Why do you need two? Why didn't you do a double major?


Discuss it with your employer, but I strongly suspect they'll prefer a 2nd Masters (they might even be assuming you'll do a 2nd Masters).