Time for action – controlling the F-Curves with the Channel Selection Panel
With several objects for Location, Rotation, and Scaling F-Curves, Graph Editor is likely to get cluttered. You need a way to choose which F-Curves you are seeing. It also helps if you can lock an F-Curve so you don't adjust it when you don't intend to use the Channel Selection Panel, as given in the following steps:
In the 3D View window, move the cursor over the Cube and select it with Shift + RMB. Note that in Graph Editor, you can see that there are now channels displayed on the left for both the Cube and the Camera, as shown in the following screenshot.
On the left side of Graph Editor, press the LMB on the triangle next to the Location channel of Camera so it points down, as shown in the following screenshot:
The X Location, Y Location, and Z Location channels for Camera appear.
Click several times on the eye symbol next to Z Location of Camera with the LMB and watch the F-Curve for Z location as you click. Scrub...