modern-web-design-and-development

The keyboard can also be used to select layers. Pressing Option + [ or
Option + ] selects the layer below or above the current layer, respectively.
Pressing Option + < selects the bottom-most layer, and Option + > selects
the upper-most. Option + Shift + < selects all layers between the current
layer and the bottom-most layer, and Option + Shift + > selects all layers
between the current and upper-most.