Can someone explain this wiring to me?

It sounds as if the electrician miss spliced the conductors turn the power off remove both switch's you will see wires leading to the bottom of the switch trace them to the splices one of the splices will have three leads together this is the one you want to open connect one conductor at a time to the switch turn your power back on and id the fixture which lights up .Repeat this until you have the two outside lights id and then tie them into the wire from the other switch.