[Garkin]

This is a little offtopic, but all button data is stored in tabFilters table, so it would be easier to work with this table:

local function InvTabSwitch(_tButtonData)
    -- do stuff --
end
     
local function HookBankButtons()
    local inventory = PLAYER_INVENTORY:GetDisplayInventoryTable(INVENTORY_BANK)
    local tabFilters = inventory.tabFilters
       
    for k,tButtonData in pairs(tabFilters) do
        local hCallback = tButtonData.callback
           
        -- Make the SubMenu bar for this button & store it in tButtonData
        local button = inventory.filterBar:ButtonObjectForDescriptor(tButtonData.descriptor)
        local menuBar = MakeMenuBar(button.m_button)
        tButtonData.FilterIt_SubMenu = menuBar
 
        tButtonData.callback = function(...)
                InvTabSwitch(...)                      
                hCallback(...)
            end    
    end
end

EDIT: As merlight has explained, "buttonData.control" is not supported by MenuBar / MenuBarButton class and it is not correctly updated by inventory manager. So, I have updated code to get button from descriptor.