Zabbix at the moment has three levels of macros:

• global macros
• template macros
• host macros

I'm proposing:

• add yet another layer of macros between template and host macros - hostgroup macros
  The best place to add such feature in zabbix web frontend is probably http://zabbix.server/hostgroups.php?form=update&groupid=group_id
  Also in hostgroups table possible it would be good to have summary info about number of groupmacros macros (in second column with templates and hosts)
• it should be possible to track inheritance of the macros (probably best place would be http://zabbix.server/hosts.php?form=update&hostid=host_id -> Macros tab) that some host macros are overwriting template global, template or hostgoup macros