[siweia]

What I currently do is add a new attribute in 'updateAura'.

button.spellID = aura.spellId

local BOLSTER_ID = 209859
 
local function PreUpdate(element)
    element.numBolster = 0
end
 
local function FilterAura(element, _, data)
    if data.name and data.spellId == BOLSTER_ID then
        element.numBolster = element.numBolster + 1
        return element.numBolster == 1
    end
end
 
local function PostUpdate(element)
    if element.numBolster == 0 then return end
 
    for i = 1, #element.sortedBuffs do
        local button = element[i]
        if button.spellID == BOLSTER_ID then
            button.Count:SetText(element.numBolster)
            break
        end
    end
end