Custom option ; dropdown in option group option doesn't seem work

[echo minnow]

Here is simple WA (https://wago.io/OoVdRX5AA) for testing dropdown function. There are two dropdowns in the WA (in option group / out of option group). But a dropdown in option group is not work. Am i doing something wrong?

local optionTest = aura_env.config["dropdown"] -- dropdown is out of option group (worked)
local optionTest_ingroup = aura_env.config["option_group.dropdown"] -- dropdown  in option group (not worked)

if optionTest == 1 then
    print("option 1");
elseif optionTest == 2 then
    print("option 2");
elseif optionTest == 3 then
    print("option 3");
end

if optionTest_ingroup == 1 then
    print("option 1 in group");
elseif optionTest_ingroup == 2 then
    print("option 2 in group");
elseif optionTest_ingroup == 3 then
    print("option 3 in group");
end

Custom option ; dropdown in option group option doesn't seem work

[echo blade]

You are indeed doing something wrong

Config.options_group.dropdown

Config["options_group"].["drop-down"]

That are your options to access it