Sales organization, distribution channel and division together are called sales area.
It means certain sales organization can operate certain division through certain distribution
channel. Here, I will show how to set up sales area.
Step1: Enterprise Structure--->Assignment--->Sales and Distribution
--->Set up sales area--->click 'Clock' icon

Step2: select sales organization, and then click 'Assign'

Step3: select Distribution Channels, and then Enter.

Step4: select distribution channel, and then click 'Assign'

Step5: select Division, and then Enter
Step6: save it