Some curious use of (or lack of) colour coding there!
It looks like the top and bottom sets are all pairs of contacts arranged so either the bottom pairs are joined (as shown in the photo) or in the other position, just the top pairs are joined.
It is possible there is a middle mechanically stable position with nothing linked.
I also think I see the left sides are linked, so the common terminals are the lower R/Y/B ones, and currently they go to the lower black ones (except far left, seems not used?)
In the other switch position they go to the top R/Y/B wires.