Open two instances of a file in a single Visual Studio session

Here’s how to do it…

1. Select the tab you want two copies of
2. Select menu Window → New Window from the menu.
3. Right click the new tab and select New Vertical Tab Group

If New Window is not listed in the *Window menu note that the command does exist, even as of Visual Studio 2017. Add it to the Window menu using menu Tools → Customize → Commands. At that point decide where to put the New Window command and select Add Command.

UPDATED on “30 July 2018”

In Visual Studio Code version 1.25.1 and later

Way 1

You can simple left click on your file in the side-panel (explorer) and press Ctrl + Enter.

Way 2

Simply right click on your file in the Visual Studio Code side-panel (explorer) and select the first option open to the side.