For more information about the layout options of the Gradebook in Course Site, please visit - http://docs.moodle.org/en/grade/report/grader/index#Layout
Go to Administration>Course administration>Grades.
Adjusting Columns View in the Gradebook
If you cannot see all of the columns ore you would like to restrict which columns you can see, you may need to adjust your view.
The screenshot below shows the icon to click on to change your view.
Sorting Grade Columns
You can sort by clicking on the up/down arrows located next to the title in the column you want to sort.