Hi Can you be more specific about "main filter"????
any screenshot or sample data please???
Context Filters Will always FILTER the Data First. So your Second Filter Would act after That. CONTEXT filter would limit the data in first Step so that your second filter would act on it. So try adding second one to context too.
If I understand correctly, you're trying to say that the dimension (main) filter does not have any effect on your context filter? If so, please refer to the Tableau's Order of Operations. In your case, Tableau processes Context filter first before processing the dimension filter. So you need to be analytical on what you use as a context filter and what as a dimension filter.