Hi,
I’m not sure if I understand correctly yet:
– Do you want to display a filter, but restricted to a specific category of the current page?
– ..or you don’t need the filter, just restrict the results to the category of the current page?
– ..or the filter should be visible and set to the category of the current page?
Let me know, and I may be able to suggest a solution, although it may require a bit of custom code as well.