How to collapse subforums on home page for users

Im in the process making a forum for a game, my problem is that I have many sub-forums and even sub-sub-forums.

http://darksummoner.forumotion.com/

I want for the user to see only the top level categories.
Found a question like this, but the instructions were out of date, and I do not wish to deal with code.

how can this be done?

Hello,

Display // Index Packing // Medium

Thanks, my editing was in "simple", not "advanced". Thats why I couldn't find the index packing option that the answer I googled directed me to open