[gglnx]

That's a little bit complicated. Yes, the law behind German works councils (Betriebsverfassungsgesetz) only applies to workers employed in Germany (Territorial principle), but the Federal Labour Court (Bundesarbeitsgericht) has ruled that international employees could also be govererned by the German works councils, if international employees are integrated into the German part of the company and are really depended on management in Germany (»„Ausstrahlung“ des Inlandsbetriebs« [1]). But it's a narrow definition.

But the law doesn't forbid applying agreements between the management and the works council (Betriebsvereinbarungen) to employees outside of Germany.

[1] https://www.vahlekuehnelbecker.de/2018/10/19/wann-ist-der-be...