Kevin, I fitted exact one today, if you notice both strips are the same, and each one has one end closer to a slot than the other end.
Take the ends with the slot closest to the end and slot the two together. One of your five bolts goes in that “joined up” and overlapped slot.
then use two bolts for the bottom strip, two bolts for the top strip.
That's how I assumed they would be joined, it just didn't seem right as the bolt hole when together doesn't line up there is a slight overlap, I assume that gets worked out when they are screwed into the blockwork