Collapse Everything Else Extension for Visual Studio
A simple Visual Studio extension that allows you to collapse all outlining sections in the current document except for the currently highligted one.
Adds a new menu item:
Edit > Outlining > Collapse Everything Else
By default, the command is bound to the shortcut key
Ctrl+M,S (e.g. Collapse 'some').
Install this extension using the .vsix from the latest release.
For more details on the implementation of the extension, see the writeup I did of the process.