I made this a long time ago... but still works
You can see the staircase to go up to departure level right behind the black car. This walk from TBIT arrival hall to T3 check in counter takes about 90 seconds if you are able body person (add another 30 seconds if you use an elevator to get from arrival to departure level). From T3 to T2, it is another 5 minutes or so.
Taking the land side terminal bus going the wrong way around the circle from TBIT to T3 or t2 will take you about 40 minutes in traffic.
Going back to TBIT and clear security there and walk the long way across the entire north wing of TBIT to the air side bus station to T3 or T2 will take at least 30 minutes.
Your choice...
Here is the link to the current google map streetview of the upper departure level:
https://www.google.com/maps/@33.9443...7i13312!8i6656