This is how I install xfce4 on a new Debian:

yes | \
  for x in `apt-cache search xfce4 \
      | sort \
      | awk 'BEGIN { FS = " - " } { print $1 }'`; do \
    apt install $x; \
  done

Or if you prefer a less transactional install, you can use xargs

apt-cache search xfce4 \
  | sort \
  | awk 'BEGIN { FS = " - " } { print $1 }' \
  | xargs apt install -y