You're making it more complicated than it should be.
A combo cap is internally built like this
1--C--2, where 1 goes to capacitor of one size, and 2 goes to capacitor of another.
If you were to buy two of them separately you'll have
So you butt two capacitors together like this at the **. Where you have the **, you'll hook it up as if it was the common terminal. Orientation doesn't matter.
You're going to want to use female-female-male Y cable. Imagine that its duct taped together and all you see are the three terminals. It helps to form mental image of the schematic.