Click Sectioning Tools tab > Mode panel > Planes .
Click the Current Plane drop-down on the Planes Settings panel, and select the plane you want to customize, for example, Plane 1.
This plane becomes the current plane.
Click the Alignment drop-down on the Planes Settings panel, and click Align To Line .
The cursor changes to a target .
In the Scene View, click somewhere on the line you want to align to.
Navisworks updates the position and alignment of the section plane, so that it is placed at the point you clicked.
To save the current sectioned viewpoint, click Sectioning Tools tab > Save panel > Save Viewpoint .