如何使用Regex将字符串分割为2D数组?

I've got a problem that seems simple on the face of it but has defeated my meager regex skills. I have a string that I need to convert to an array and then process the values accordingly, which is simple enough, but the format of the string cannot be changed (it is generated elsewhere) and the logic of it has me baffled.I've got a problem that seems simple on the fac