I might have misread your original post.
Are you asking what processors your motherboard supports to upgrade it?
The Chipset is for the motherboard and not for the processor. What determines what processor you can use is the Motherboard Socket which for the Ryzen processors is AM4 and the Motherboard's CPU SUPPORT LIST and BIOS Version.
It uses a AM4 Socket but you need to go to Lenovo Support to see their CPU SUPPORT LIST to find out which processor your PC supports including which BIOS version you need to recognize the new processor.
Your PC is similar to a laptop so you will either need to open a Lenovo Support ticket to find out which AM4 processor you can upgrade to or ask Lenovo's Forum.
NOTE: You PC Hardware Manual mentions how to replace the processor but doesn't mention which models will work in your AIO PC.