How to use zoom extents button

To use zoom extents button

Step 1

You need to center and magnify the view in all non-camera viewports to display all visible or selected objects. The picture below shows the sphere that is not in the center of the viewport. You need to select the viewport by clicking at it.

Step 2

Now, click the zoom extent button as marked by the picture below.

Finally, sphere will be adjusted to the center.