/<path to file 1>
/<path to file 2>
/<path to file 3>
or use multiple --include rclone copy / --include="/<path to file 1>" --include="/<path to file 2>" --include="/<path to file 3>" :someremote:/path/to/directory
and there are more options, depending on the real path names and filename extensions.
welcome, yeah, rclone is flexible, often multiple ways to get something done.
filters apply to the source, as per rclone docs:
"To test filters without risk of damage to data, apply them to rclone ls, or with the --dry-run and -vv flags."