mysql> select * from icinga_hostgroups where alias = 'Nagios-/Icinga-Server' LIMIT 0 , 30;
+--------------+-------------+-------------+---------------------+-----------------------+
| hostgroup_id | instance_id | config_type | hostgroup_object_id | alias                 |
+--------------+-------------+-------------+---------------------+-----------------------+
|        11255 |           1 |           1 |                1298 | Nagios-/Icinga-Server |
+--------------+-------------+-------------+---------------------+-----------------------+
1 row in set (0.00 sec)

mysql> select * from icinga_hostgroup_members where hostgroup_id = 11255 LIMIT 0 , 30;
+---------------------+-------------+--------------+----------------+
| hostgroup_member_id | instance_id | hostgroup_id | host_object_id |
+---------------------+-------------+--------------+----------------+
|              201028 |           1 |        11255 |            989 |
|              201029 |           1 |        11255 |            999 |
|              201030 |           1 |        11255 |           1000 |
|              201031 |           1 |        11255 |           1121 |
+---------------------+-------------+--------------+----------------+
4 rows in set (0.00 sec)

mysql> select display_name from icinga_hosts where host_object_id = 989 LIMIT 0 , 30;
+--------------+                                                                     
| display_name |                                                                     
+--------------+                                                                     
| lin1933      |
+--------------+
1 row in set (0.00 sec)

mysql> select display_name from icinga_hosts where host_object_id = 999 LIMIT 0 , 30;
+--------------+
| display_name |
+--------------+
| lin9007      |
+--------------+
1 row in set (0.00 sec)

mysql> select display_name from icinga_hosts where host_object_id = 1000 LIMIT 0 , 30;
+--------------+
| display_name |
+--------------+
| localhost    |
+--------------+
1 row in set (0.00 sec)

mysql> select display_name from icinga_hosts where host_object_id = 1121 LIMIT 0 , 30;
+--------------+
| display_name |
+--------------+
| lsvrzlxsv48  |
+--------------+
1 row in set (0.00 sec)