How to see through trees and foliage during battle?

If you press and hold the space bar during Battle mode then an option menu pops up. This allows you to enable / disable various things, one of which is to 'Hide foliage'. Once checked, during battle press and hold the space bar again to see your troops through trees or alternatively you can click the "lock" icon next to the 'Hide foliage' option so it will hide automatically.