Command name for Collapse All,Expand All Nodes in XML Editor

From Tools->Options->Environment->Keyboard->mapping scheme (Default)

• Expand all: CTRL + M, CTRL + X
• Collapse all: CTRL + M, CTRL + A

For selected areas:

• Expand selection: CTRL + M, CTRL + E
• Collapse selection: CTRL + M, CTRL + S

Its Edit.ExpandAllOutlining and Edit.CollapseAllOutlining i think.

See Menu Edit->Outlining in Visual Studio. Here´s the reference from MSDN

• Hide Selection (CTRL + M , CTRL + H) - Collapses a selected block of code that would not normally be available for outlining, for example an if block. To remove the custom region, use Stop Hiding Current (or CTRL + M, CTRL + U). Not available in Visual Basic.
• Toggle Outlining Expansion Reverses the current hidden or expanded state of the innermost outlining section when the cursor lies in a nested collapsed section.
• Toggle All Outlining (CTRL + M, CTRL + L) - Sets all regions to the same collapsed or expanded state. If some regions are expanded and some collapsed, then the collapsed regions are expanded.
• Stop Outlining (CTRL + M, CTRL + P) - Removes all outlining information for the entire document.
• Stop Hiding Current (CTRL + M, CTRL + U) - Removes the outlining information for the currently selected user-defined region. Not available in Visual Basic.
• Collapse to Definitions (CTRL + M, CTRL + O) - Collapses the members of all types.