In addition to the entry (NGI / AdminVector), another dataset is available in bulk for free and openly licensed http://statbel.fgov.be/en/statistics/opendata/datasets/tools/big/SH_STAT_SECTORS.jsp
Shapefile and GML file, containing the geographical shapes (polygons) of the smallest statistical unit, which is a subdivision of an administrative unit.
Each unit also mentions the name of the administrative municipality it belongs to, and also the province, region etc, as explained in the “notice explicative”