Fixing to remodel my bathroom and the cabinet pictured below is perfect for what I have to work with. It's a total custom job. How did they do it? Telescopic slides on the backside of the "drawer"? Seems like one at the bottom and one at the top with a typical capacity of 75 pounds would work.
The big slide-out is on a pair of Blum soft close and has a single Accuride to stablize it at the top. 150 pound capacity. I built it from scratch and the slides are full extension.
The small one was bought as a finished (minus the cabinet box and the front) unit and slides on a bottom mounted pair of Accuride slides. They are not full extension. Not sure but probably about 40 -50 pound capacity. There is no stabalizer on the top and it wigggles and shakes quite easily.
They probably used full extension ball bearing side mounted slides. There are a couple of different ways to go about it. Since the right side of the pullout is not visible you could simply mount one slide at the top and one at the bottom of the pullout. You would then mount the other half of the slide to the side of the cabinet. It would be nice and easy to install but just about impossible to remove if you ever had to to do any maintenance since there will only be a 1 1/4 inch gap between the wall and the side of the pullout (assuming you build it Euro style like in the picture).
Another option (and how I think the one in your picture was built) would be to build a sub frame that would fit under the pullout. From the front looking in to the cabinet picture a u shaped assembly that would fit under the pullout. Each side of the U would be approximately 2" tall and the base of the U would be the inside width of the pullout minus 1 1/32 for the hardware. The hardware would mount to the side of the U and to the inside side of the pullout. With it being that narrow tall you would want a 3rd slide at the top or install a couple of plastic buttons for the top of edge of the opening to stabilize the pulllout. If you are still working on it I could make it much clearer with an illustration. Just let me know.
I'm pretty sure the glides/slides are on the bottom, as shown by the deep valance on the bottom of the pull-out. It is not apparent if there is a stabilizer on the top. It would make sense to have one on the top.
