You just write Amsterdam or Brussels. 

Thank you very much for your help.  I thought this but want sure as obviously they have more than one station .  I need yo stop over thinking

Don't worry about it. In Belgium you travel to zones. If you write "Brussels" you can get off in 30+ stations in the Brussels capital region.

You can also abbreviate to Brussels C, Köln Hbf, Paris GDL (Gare De Lyon),... . Still clear for anyone checking your tickets . And even if you don't mention the exact station, nobody is gonna say something about it. 

Enjoy your trip!