Filters
folder within my user's Library
folder:/Users/my_user_name/Library/Filters/
Macintosh HD > Users > my_user_name > Library > Filters
Library
folder is normally hidden. An easy way to navigate to it is to click on the Go menu in Finder and while the menu is down hold the Option key. Library
will then appear in the list. Once you open it you can create the Filters
folder which probably doesn't exist, and put your filters there.