Modify panel > Select a spline sub-object. > Modifier List > Delete Spline
Modify panel > Select a spline sub-object. > Modifiers menu > Patch/Spline Editing > Delete Spline
The Delete Spline modifier provides parametric deletion of spline geometry based on the current sub-object selection level in the stack. The possible selection levels include vertices, segments, and splines. Apply the Delete Spline modifier to delete the geometry specified at that sub-object level.
To use the delete spline modifier:
Apply a Spline Select modifier and select a section of the spline for deletion.