The selection refinement feature can be applied to any unit selection
operation. To configure the selection refinement, right-click
.
To toggle selection refinement on or off, left-click the same button. While
selection refinement is active, any selection operation that selects multiple
units will be narrowed down according to the selected refinement criteria. While
selection refinement is in effect, the button will take on the following
appearance:
.
To apply the configured selection refinement to the current selection, press [Backspace]. Note that you do not have to have selection refinement turned on to be able to apply it to the current selection.