I know a consulting company which has made such connector and I know there are some attempts to build new independent Open Source adapters but so far there is no component available to do this job. Mostly Essbase will be filled with MaxL scripts and read out in the same way.
Essbase is an OLAP tool and accepts MDX queries. If you need to unload the whole data you will probably get a very huge amount of data because of the amount of dimensions and the necessary cross products.
An alternative representation of this structure would require a three-dimensional spreadsheet grid, giving rise to the idea that "Time", "Account", and "Region" are dimensions. As further dimensions are added to the system mcdvoice