Funny enough, not on the default Files app, but at least on an officially-supported client (plus most "good" file managers I'm aware of.)

Something I dislike with Apple products is that so much basic functionality is locked behind expensive apps. I need to pay $10 to get a calculator on my iPad or $20 to control audio volume per-app on MacOS. So it's very refreshing to me that Samba support is built in to Files.