Wheat = farmers

Hammer = workers

Compass = intelligentsia

It's a funny story actually. At first the DDR had no official symbol and just used the tricolour German flag in use today. At first they just used Red Army seals for documents, since the administration was overseen by the Red Army. Then they hastily made seals for IDs and passports, which futured just the hammer in a circle, and then later added the wheat, but no one really liked it, as it looked very unofficial. In 1953, as they started establishing a real government autonomous from the Soviet occupation force, they needed to use seals to sign new laws. So someone modified the existing seal and added the compass, to make it more official-looking. In 1955, they needed to make more seals for signing government documents, so they used the one from 1953 as a blueprint. And eventually in 1960 they decided it was actually a pretty good emblem, so they put it on the flag. Which made West Germany immediately pass laws banning its display anywhere.