There are 2 sets of rules with this name.
Napoleonic[]
The inspiration and model for this rules set has come from two very fine existing published rules sets. They play fast and are easy to pick up.
http://blackdogofdoom.blogspot.co.uk/2010/09/brigade-commander.html
Modern[]
Each model represents about 4 vehicles, inspired by an article in Wargames Illustrated many years ago. http://www.wargames.watkins-family.co.uk/modern/brigadecommander.htm