You can do it with math.
a/n = N Step
Where a is the actual angle of the object and n is the number of angles in a step.
For instance, if your N Angles is set to 4 then the number of angles in each step is 90. If your object is at 270 degrees then:
Your N Step is 3.
If your N Angles is 8 then the number of degrees per step is 45. If the angle of your object is 225 then:
Your N Step is 5.
The result is zero-based so if your object is facing right, your N Step will be 0. So for an N Angles of 4, you'd get steps of 0, 1, 2, and 3.
It seems to me it would be easier just to compare the actual angle of the object, though.