I've seen a couple of these switches before. Sometimes they have the line side already internally connected (or with a tab you can cut if you want them to be separate on the line side. I'd have to see a picture of the back side of it to tell you. But yeah you just need the one line side (with maybe a jumper if it is internally separated), and each switch leg connected to the other side of each switch.

If there is a ground stud on the switch (probably), ground it also.