In the finder menu choose "Go" the "Go to Folder" option and then paste this link
~/Library/Group Containers/243LU875E5.groups.com.apple.podcasts/Library/Cache
Some one else gave that answer..It works on my M1Mini. the podcasts aren't the names in Podcast APP.
When you control click on a file it will give you the option to quick view it so you can see if it's the one you're looking for. if it is drag it on to the Music APP and it will import that file and it will have its' proper name.
Unfortunately you can't change the download location in Podcasts. But once it's in music it can be stored on an external hard drive. You can change where Music stores its files. Preferences, then Files.
Richard
PS Here's the original link for the answer
Podcast saved files location - Apple Community