That display is part of the AFS (Auto Flight System) Control Panel on the FCU (Flight Control Unit):
(Airbus A340 FCOM - Auto Flight - General)
The general idea of the FCU is that you can push in the knobs, which will put the respective autoflight mode in an automatic setting (called managed mode) and show dashes in the display, and you can pull the knobs out and then rotate them to manually overwrite values (called selected mode).
In your example, the display currently shows:
- SPD 250: The autothrust system is maintaining a manually selected speed of 250 knots.
- HDG ---⚫: The lateral autopilot mode is in managed mode, meaning the aircraft will follow the flight plan programmed into the FMGS. See also this answer.
- ALT 08000: The current target altitude for the autopilot is 8000 feet.
- V/S -1000: The vertical autopilot mode is to maintain a manually selected descent of 1000 feet per minute.
The FCU allows you to switch between selecting a heading (HDG) vs. a track (TRK) and a vertical speed (V/S) vs. a flight path angle (FPA) with the button at the center. The HDG and V/S in the center of the display mean that the current mode is in heading and vertical speed.