Look at the diagrams in the For Reference section and think about the way an intermediate switch works - as long as you can tell which cores are from the same cable you'll be OK. If you don't get the "symmetry" that you want from the rocker positions, turn the switch upside down, or swap the cables from top & bottom.
If you can't tell which cable is which, connect them up anyway - since all you are doing is switching live from one route to another you can't end up with anything dangerous. If you end up with a situation where in 1 position of the intermediate switch the next 2-way one does nothing, swap either the blues or the yellows round.
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