I'm trying to create a toolbar/menu as in the image below.
I've added a toolstrip control. It has some buttons with images and text below. But I don't know how to reproduce the "grouped" look in the image above.
Does someone have an idea how to do that?
The control in your image is a ribbon (not a toolbar, toolstrip or tooltip).
WinForms doesn't support ribbons out of the box. But it looks like there are ribbon controls available, such as RibbonWinForms on GitHub.