It is below the Motion graphs, at the left side of the Motion toolbar.

First, before you can use the Motion-Law Selector:

1.Click a above or below a segment to move the program focus to MotionDesigner.

2.Click above or below a segment to make it the Selected-Segment

Now, use the Motion-Law Selector to:

•Identify the Motion-Law of the Selected-Segment

AND/OR

•Use the drop-down to select a different Motion-Law for the Selected-Segment

See also Motion-Laws