Groups containing other groups or nested grouping

We are currently monitor multiple application suppose a,b ,c application that application contain (application ,database server , networking gourps ) so we need to add "a" as main group so that we can add ((application ,database server , networking gourps ) these group as sub goup under the mail goup "a"

we have check some links but not sure are these working for for version 2.4.6
https://support.zabbix.com/browse/ZBXNEXT-1262
https://www.zabbix.com/forum/showthread.php?t=43743