Different types of work-related German courses are available in Germany: there are basic modules (where you can improve your general language skills) and special modules (which often focus on specific themes). In the basic modules, you can begin at the B1, B2 or C1 level and study until the C2.
In the special modules, you can, for instance, learn technical terms related to your job. If you have not passed the integration course, you can start these special modules at a lower level (i.e. A1 or A2).