Pretty sure that is stored in a file in your eq folder which is your charactername_servername.ini so if your character was called Kelton and you play on Povar it would be kelton_povar.ini
If you copy the whole file it will also have lots of other stuff like hotkeys, combat abilities, blocked spells, etc. So if you only want to copy filters you can go to [ADDITIONALFILTERS] section and just copy that into the file for your other characters. There is also another file which stores all of your UI info, which is called ui_charname_servername.ini so using above example again it would be ui_kelton_povar.ini.