How to hide some specific attributes from top level categories
In Improved Layered Navigation it is possible to show different attributes related to the category. For example category 1 shows attributes A B C, category 2 shows attributes A C D, category 3 shows A B F G.
To set attribute visibility per category level or exclude filters from some categories, navigate to Catalog > Improved navigation > Filters > your filter page and make changes there
See more details on Improved Layered Navigation page
See more details on Improved Layered Navigation page
See more details on Improved Layered Navigation page
See more details on Improved Layered Navigation page