Two of the students in Sandy's acting class perform a scene from Two and a Half Men (2003) and Sandy tells them that "okay, that was one way to rip off The Odd Couple". Both Two And A Half Men and The Kominsky Method (2018) were created by Chuck Lorre.
As noted, Michael Douglas's Sandy watches his students perform a Two and a Half Men scene, which was created by Chuck Lorre. Another important connection: the sitcom famously starred Charlie Sheen, who played opposite Douglas in Douglas's Oscar winning role, Wall Street.
Michael Douglas's Sandy and the character played by Paul Reiser have a short debate on comedy acting. Reiser began as a standup comic turned actor (mostly comedy with some drama). Their discussion began with Sandy discussing sitcoms, which Reiser is best known from Mad About You.