BuddyPress.org

And re. number of members to show per page, try this …
(You can change the “100” to anything you like.)

add_filter( 'bp_after_has_members_parse_args', 'show_more_members' );

function show_more_members( $args ) {
	if ( bp_is_members_directory() ) {
		$args['per_page'] = 100;
	}
	return $args;
}