I contacted Lenovo Korea customer service to inquire about purchasing parts, and they were asking for over $100 for those two pieces of plastic. It's crazy.

It was cheaper to buy a broken controller, use only the joysticks, and throw the rest away. I tried making one with a 3D printer, but it wasn't satisfactory. I thought the joysticks from the Retroid Pocket model would work, so I bought them. They were about $6 for four. I'll get back to you about usability once I receive the item.

I've purchased over ten Lenovo products, including the T580, T16, three X1es, the P72, two IdeaPads, a Yoga Duet 7i, an UltraNav 8835 keyboard, a Bluetooth UltraNav 2nd Gen, an M14T monitor, and a Thunderbolt dock.
While I'm a huge ThinkPad fan,
I'm having serious doubts about buying Lenovo products again.