BuddyPress.org

BuddyPress works like a central community, so it’s either you have one BuddyPress website or not.

What you can do is to install it on a single subdomain.

like community.abc.com

then you would have to edit your wp-config.php file, add the following line

define ( ‘BP_ROOT_BLOG’, 3 );

the number 3 is your blog id.

I’ve found the solution from

http://premium.wpmudev.org/forums/topic/how-to-install-buddypress-as-a-sub-domain

Thanks to Sabuntu!

I’m requesting the subdomain installation as a feature though.