If you want you can draw two paths: one for the camera to move along (camera path), and a separate one for the camera to focus on (target path). This would be like watching an airplane from a moving car.
If you want your camera to focus on a target path, you need to draw the camera path using the Specify Target option. Once you have drawn both paths, you need to snap the camera path’s target point to the target path.
Step One: Draw the Target Path
Select Tools
> Animation > Insert Path, or click the Insert Path button
on the Animation toolbar.
In the Path Properties dialog, give the target path a name.
Click OK.
Pick points to define the target path, then right-click and select Finish.
Select Tools
> Animation > Animation Properties, or click the Animation
Properties button on the Animation toolbar.
If you do not want to include the target path in your animation, uncheck the Include check box beside the target path’s name in the Animation Properties dialog.
Click OK.
Step Two: Draw the Camera Path
Select Tools
> Animation > Insert Path, or click the Insert Path button
on the Animation toolbar.
In the Path Properties dialog, give the camera path a name.
Enable the Specify Target option.
Click OK.
Select the start point of the camera path.
Select a random target point. You will snap the target to the target path later.
Select the remaining points of the camera path, then right-click and select Finish.
Step Three: Connect the Paths
Click on the camera path to select it.
Click and drag the target point (the point at the end of the arrow) to the target path, then release your mouse button. The target point automatically snaps to the camera of the target path. You are now ready to preview the animation.
When you preview the animation, you’ll notice that the camera moves along the camera path and focuses on points along the target path as the animation plays.