The middle level are now called Universities of Applied Sciences, which give out a bachelors, but as far as I know never a masters diploma.
The lowest level are vocational colleges, which don’t give you any internationally recognized credential at all (but do train you to do a variety of occupations).
You basically get sorted into one of these levels once you leave elementary school based on educational skill and aptitude (by your final year teacher), and while changing is possible, it costs you years (which still seem very precious at the time).
If you meet any Dutch person outside the Netherlands they almost per definition are middle level or higher, because anyone without a bachelors diploma often doesn’t get to immigrate (depending on country).
Netherlands seems fairly egalitarian by contrast to these other systems.