Comment 15 for bug 1637878

I agree that s/he was wrong for assuming nobody used that feature, but the feature was returned in Plasma as of Ubuntu 18.04 and is still there in 18.10 (plasma-nm: 5.13.5-1ubuntu1).

If you're not seeing the virtual connections, then right-click on the network manager applet, select "Configure Networks" and then check the box for "Show and configure virtual connections."