BuddyPress.org

@pedropapito BuddyPress is installed by default in the main site. If you want BuddyPress to be “installed” in sub.dominio.com, then you’d have to add the following to your wp-config.php file:
define ( 'BP_ROOT_BLOG', $blog_id );
That way, the avatar link would go to the profile page of the member in sub.dominio.com and not to the main site.
reference: https://codex.buddypress.org/user/install-buddypress-on-a-secondary-blog/