Select all groups/components/blocks

Hi guys

I am new to SketchUp and are working on a large model of a school, where the architects have used a whole lot of groups and components. I am using the model for daylight simulations where groups often create problems, so I would like to select all groups to explode them. Ctrl + A selects everything, including curves and surfaces, which I’m not interested in.

Is there a way to select all groups without selecting other geometry?

Thanks in advance

Select them in the Outliner.