Right-click in rectangular graph, pick Zoom Data, click+drag to reset x+y axis range, drag across x or y axis to zoom x or y only.
For example, see the IV curve graph below.
You can zoom on an area with the right click command.
and if you selected an area as shown below:
The resulting view would be shown below. Notice you do not see the graph name or legend anymore.
Alternately, the zoom data command does something different.
Then selecting the same area as above, the graph will look like below.
Note, when you want to remove the axis zooming, right click and select Restore Axis Setting.