There is a view on the drawing that has been clipped. The boundary does not show the entire assembly.
Solution
1. Hover over the view border, MousButton3-->Settings.
2. Expand 'Common' and highlight 'Perspective'.
3. Select the 'Fit Planes to Extent' icon.
4. Select 'Apply' in the Settings dialog.
5. Toggle off both 'Enable Front Clipping' and 'Enable Back Clipping'.
6. OK the Settings dialog.
7. Update the view.
Notes and References
Hardware/Software Configuration
Platform: all
OS: n/a
OS Version: n/a
Product: NX
Application: DRAFTING
Version: V12.0.2
Function: DRAWING/VIEW
Ref: 001-9559257