If you want another shape besides a circle or rectangle and standards aren't going to get in the way, you can do this:
1. Create a detail view using the Rectangle type (I prefer corner to corner). Within the Detail View dialog, set the Label on Parent value to nothing (for now).
2. Define the detail, place the view.
3. Right click on the detail view and Expand the view. Manually draw the boundary that you want. Ellipse doesn't work. Lines, arcs (circles) and splines do. Expand back out of the view.
4. Right click on the detail view again and select Boundary. Now define the View Boundary as Breakline/Detail. You can set the Label on Parent to be Boundary and your View Dependent curves should now appear over the parent view.
5. Manually add your detail label on the parent view.
Some things to note:
If you need to change the shape of the detail view boundary, you will need to make the boundary Manual first, then edit the View Dependent curve(s) and repeat step 5. Sometimes after updating, brown points may appear around the detail view. A refresh will wipe the display clean.
Hope this helps.
Tim Flater
NX Designer
NX 8.0.3.4
Win7 Pro x64 SP1
Intel Xeon 2.53 GHz 6GB RAM
NVIDIA Quadro 4000 2GB