Hey there Burr, I missed you mate.

Do you mean, Is the "single object can belong to more than one Group" still waiting to be implemented?

If so, I believe so, the 'Group' section is not functional yet for this beta.
If not, you can apply different styles to an object, like a cube can have each face a different style (6 colours) and same with the edges, but as you know surface colours are coming later so you won't see anything, when you apply a style to a single solid surface, it's applied a style, just not visually yet.
Otherwise I don't think it's possible to have a single entity take on more than one style, unless I've missed something.

Cheers