By default, all rockettheme templates' fusion menu is drop-down style, if I make it split, then the submenu would appear in the sidebar. Though I like the submenu style of rockettheme.com, how can I make submenu like this?
Some of our templates support that kind of menu but not all of them. You could do two things:
1. find template that does support it and see how it is implemented in it so you can copy the code to some other template. That requires coding skills so you have to decide if you are up to it
2. publish another menu module under main menu and limit it's menu item's from level two onwards