Changed the code in functions.php to this:
function get_user_role() {
global $current_user;
$user_roles = $current_user->roles;
$user_role = array_shift($user_roles);
return $user_role;
}
And in the sidebar.php:
<?php
if (is_page(array('page1')) && get_user_role('Administrator')) :
echo '<div class="widget-title">Title 1</div>' . wp_nav_menu(array('theme_location'=>'menu1' ));
elseif (is_page(array('page2'))) :
echo '<div class="widget-title">Page 2</div>' . wp_nav_menu(array('theme_location'=>'menu2' ));
elseif (is_page(array('page 3'))) :
echo '<div class="widget-title">Page 3</div>' . wp_nav_menu(array('theme_location'=>'menu3' ));
endif;
?>