The most likely cause is that there are very few jobs in Germany posted in Sweden right now. That concept id is what you need to use, but if only one employer posts an ad that’s the only hit you’ll get.
Using cities or regions outside Sweden would require the employer to enter that data, if they do, the existing search parameters can be used.
Our api:s are focused on jobs in Sweden, so right now we are not going to add jobads from other countries.
I’ll see if I can find some info on job api:s abroad