Yeah, we had them at my last office. They were made of a paper lid, fiber bag like filter for the grounds, and then a small ring of compostable plastic for rigidity. Worked great, but even more expensive than the normal K-cups. We ended up going back to making big pots of coffee because it's easy enough, cheap, and usually tastier.
IIRC, they've transitioned (or are in the middle of transitioning) to recyclable cups.
I believe you can green bin the contents (if you have that service where you live), and recycle the plastic container, with the foil seal being the only thing that goes to landfill.
To be honest, who is going to actually separate all 3 of those pieces? In Canada, President's Choice (among others) makes a fully compostable k cup that is about $0.50/pod.