You can try working with default filters. You can use multiple filter options at once like "HELPFUL|PLAYER"
Filter list:
NONE
HELPFUL - buffs.
HARMFUL - debuffs.
PLAYER - auras that were applied by the player.
RAID - auras that can be applied (if HELPFUL) or dispelled (if HARMFUL) by the player.
CANCELABLE - buffs that can be removed (such as by right-clicking or using the /cancelaura command)
NOT_CANCELABLE - buffs that cannot be removed
INCLUDE_NAME_PLATE_ONLY - includes some specific auras which Blizzard decides that they should appear on nameplates
Here is the Blizzard nameplate filter function:
https://www.townlong-yak.com/framexm...Plates.lua#140
If the default filters get you nowhere you need a custom filter. The max number of debuffs available is 40. You will probably need two loops one for buffs and one for debuffs and you need to check each one against a certain spellid or spellname and on top you can match other stuff like who casted the aura etc.
Here is how oUF provides custom filters:
https://github.com/oUF-wow/oUF/blob/...auras.lua#L186
oUF supports nameplates and thus allows you to work with a custom filter on nameplate units.
https://github.com/zorker/rothui/blo...eplate.lua#L50
If you are using any other nameplate addon you need it to support aura white/blacklisting of some sort.