VM Category module display current category and child

[greaves]

Hello,

I have a question for you (:

I have the VM category module in my category page.
I'd like that for each category, it displays only the category's child for the category I'm currently viewing :

For example I have 5 main categories, each has 6 child categories. I'd like that when I'm viewing Main category 1, it displays only the Main category 1 child categories.
Plus when I'm viewing the Main category 1 -> child 1 I'd like to display all the child categories of Main category 1.

Does anyone know how to achieve that ?
Am I clear enough ?

Thx a lot.