Restrict grid to particular segment

Applications
1

If I create a grid function for a particular function space on a segment of the grid, still the complete grid is visualized, although the grid function is only shown on the segment it is defined on.

Is there a way to only include the segment of the grid where the grid function is defined on in the visualisation?

2

If you export the grid function and open it in the Gmsh GUI, you can specify the segments for visualisation. In the menu, go to Tools → Visibility, in the tab List, choose Physical Groups in the dropdown box at the bottom, and select the surfaces you wish to show.