Right-click any toolbar > Layers
The Layers toolbar simplifies interaction with the layer system in 3ds Max, allowing you to easily organize the layers in your scene. Most of these operations are available from the Layer Manager, however the Layers toolbar provides shortcuts to several common actions, as well as the advantage of being able to work directly in the viewports.
Note: The default UI does not display this toolbar; to see it, right-click an empty portion of any toolbar, and choose Layers from the menu.
The Layers toolbar provides the following controls:
Add Selection to Current Layer
Select Objects in Current Layer
Set Current Layer to Selection's Layer