You can log in to MyXfinity.com and view your current channel lineup at https://www.xfinity.com/support/local-channel-lineup/. If you want specific bundle channel lineups, go to https://www.xfinity.com/learn/channel-lineup-bundles. For the Sports and Entertainment package, it is unavailable on the web site according to a Chat representative:
"This is a sidegrade and the channels are different for every area so the channel lineup is not available on the website. Only the channel lineup of the main package will show up on the website."
They will, however, type in the chat the package 20+ channel lineup for specific zip codes . You just have to escape the chatbot by typing 'agent' and get a live agent.