What is a kind of the curtain rod? And where can I get it? Thank you

There are double and triple tract ceiling (and wall) mount rods at Ikea http://www.ikea.com/us/en/catalog/products/80079363/
The Dining room has panels that I made- 2 layers so one slides behind the other (using a 2 tract mounted to the ceiling). and the Living room has curtains with sheers behind. I used a 3 tract in there as I wanted the option to add a room darkening panel at some point.
Very easy to mount and panels were also easy to make (and Ikea does sell panels). Curtains were a little harder to make but doable (I am a novice sewer).

@mbvv: I find this so helpful and am new at this and desperate to find something affordable and easy to deal with. My question to you is, these tracks from ikea come in 55' increments. How do you get them to look so seamless in your photos? (they are not crystal clear so maybe they aren't so seamless?) Thanks for the information above - very helpful and gives hope to the useless decorators like me.

Sorry about the delay in reply. They can be easily joined and IKEA provides the hardware to do that. The curtains flow over both joined tracks effortlessly!

The window treatments are mounted on cubicle track (sometimes called hospital track) and can be coordinated through any good window treatment vendor.