If you move the levers by hand you will notice the lever on the left in the picture causes the shaft of the lever on the right to move into or out of the transmission. This lever should be the selector for 1-2, 3-4, and 5-R. The lever on the right selects 1, 3, 5 in one direction, 2, 4, R in the other and Neutral in the center detent. Another of checking is to move the lever on the right into the center detent and rotate the transmission output shaft - it should turn if it's in Neutral. Moving this same lever in either direction will engage a gear (3 or 4) and the output shaft shouldn't turn. This assuming the transmission is mounted to the engine.
The left transmission lever in the photo is connected to shifter point that moves when the shifter lever is moved side to side. The right transmission lever in the photo is connected to the shifter point when it is moved fore and aft.