Boolean with group of multiple solids

I try to cut a group of solids with another solid. In fact it’s a cube group of multiple squares, cut with a cylinder. I need to maintain the different layers in the cube, as the interest is the interaction between the two

Can you share the model so we can see exactly how it is structured? I’m not sure from your word description, and the devil is in the details.

Ci don’t have the model right now, but I create a rectangle, then I give it a depth. So, I end up with a 3D rectangle, then I duplicate this objet in order to create a cube. Each part (layer) of the cube is of a different color. Each rectangle is a solid.
Now I want to cut this cube with a cylinder, in order to see what will be the result. I’m a woodturner and I try to anticipate the results of my work.
The pb is that as if I make a group it is not recognized as a solid.

Here are two methods, assuming I have understood your request properly and assuming you are on SketchUp Pro as your profile does not indicate what version you are using.

First with native solid tools: Create your stack of rectangles, making each one a group. leave them as separate groups. Create your cylinder that will act as a cutting shape. Use the Split option in the native solid tools to split each group using the cylinder. Then delete the unwanted groups.

That first method is really pretty simple in this case but for arguments sake and in the case of more complex geometry I’ll mention the Second: using the excellent extension Booltools 2 which can cut multiple groups nested inside.