how to drag 3d layer in curve

[Jannatul37848065k339]

I want to move the object in curve. It seems If I drag this 3d layer it creates straite line instead of curve.

[Rick Gerard · Accepted solution]

Move the CTI (Current time indicator) between keyframes, press the 'g' key to bring up the pen tool, hold down the Alt/Option tool to change the pen tool to the Convert Vertex tool (inverted V pointer), then click on the middle keyframe and drag out bezier handles. 

Maybe this tutorial I created will help you adjust the motion path.

If you want to accurately manipulate a path in 3D space, you should enable multiple views to adjust the motion path using the top, left, and front views.