To Apply a Clip Mask by Two Points

Select the Clip Mask view control.
In the tool settings, click the Apply Clip Mask By Two Points icon.
Enter 2 data points to define diagonally opposite corners of a rectangular clip element.
If only one view is open, then the clip mask is applied.
If more than one view is open, enter a data point in the view to which clipping is required.

Applying a Clip Mask by Two Points