How to unfold all category?

-- HikaShop version -- : 2.6.0
-- Joomla version -- : 3.4.5
-- PHP version -- : 5.4.45
-- Browser(s) name and version -- : Chrome

Hi ,
I put a module which shows all lv1 categories from product category.
When I click first category , the lv2 categories of the category will show.
And then I click next category , the lv2 categories of the category will show.

But the lv2 categories of first category will be folded , I don't want to do it.

I hope all cateogries could be unfolded at first time. Just like tree line.

Please give me some advices.Thx~