Dealing with MultiDimArray

I think I’ve touched on this topic before, but I’d like to understand the current status.

Let’s say I’m using a library that uses arrays of arrays. I understand that in Gamma this is translated as MultiDimArray. My question then is, is it possible to painlessly create such objects from types available in Gamma and is it possible to painlessly parse such types?

multidimarray

I don’t understand how to create such a type and how to get data from it. I remember doing it once, but how? (Or it could be a false memory)