A. Click on a motion point.
B. Move the Timeline Pointer to hit a motion point of the selected layer.
A. Click on a non-animated empty frame to select the previous motion point.
B. Move the Timeline Pointer to hit a non-animated empty frame of the selected layer to select the previous motion point.
Note that it works only when it hits non-animated empty frame.
How to?
Select a motion point, for example P2, set property values.
Purpose?
Change motion property values of a layer from time to time to create layer animation.
Why?
Assuming property values of P1 and P2 are different, that means the motion property values of the layer will change in timeline between P1 and P2, it leads the layer animate.
Example?
Click the Play Button to preview animation.