bp_core_get_userlink_by_username( string $username )

function bp_core_get_userlink_by_username( $username ) {
	if ( bp_is_username_compatibility_mode() ) {
		$user_id = bp_core_get_userid( $username );
	} else {
		$user_id = bp_core_get_userid_from_nicename( $username );
	}

	/**
	 * Filters the user link for the user based on username.
	 *
	 * @since BuddyPress 1.0.1
	 *
	 * @param string|bool $value URL for the user if found, otherwise false.
	 */
	return apply_filters( 'bp_core_get_userlink_by_username', bp_core_get_userlink( $user_id, false, false, true ) );
}