+1 for this feature. I have to deploy environments for different customers, each env has about 100 servers and we have Host Group per Customer in Zabbix.
It would be really helpful if I can define macros per Host Group (per customer).
I would want HOST->HOSTGROUP->TEMPLATE, but "configurable" is probably the correct way to set it up.
For dealing with hostgroup collision (e.g. two hostgroups supply a user macro
{#FOO}), this could be handled with any kind of sort, with the "first" item winning. It would probably be nicer if user macros (or the host groups themselves) could be assigned priorities as well as values, in which case sorting on the priority would be natural and perhaps easier for the user to plan for in light of mandated naming schemes.
bump. We have a need to set different thresholds based on environment and location, so as a result, we have to create inheritable templates that simply have the purpose of holding macros and no new items
Host group level macros which follow the HOST->HOSTGROUP->TEMPLATE chain of command would greatly help manage the adjustment of thresholds and other values.
This would be a huge feature for us to since we are managing over 40 different clients of ours. Is this even being considered to be added or not?
Maybe you can "team up with other users to commonly sponsor implementation" of this feature.
Just wanna point out that this option exists, since it was not obvious to everybody in the past.
I just wanted to create user macros inside my host groups and then discovered this feature request. Would love to see this implemented in one of the next major releases!
how should this work when a host is a member of several groups ?
Let us build our own hierarchy of groups (f.e. with a integer):
1. Global
2. Template
=> Group 1...1001...n
5. Host (we can correct all conflicts here)
Would be quite useful for me, having ansible pull host info from zabbix.
richlv: i'd imagine host macro would overrule group one
Setting macros using Hostgroups? Good idea and also with: Theese macros also should set level of insertion in hierarchy Global, 
, Template, , Host , - to replace prev. level of stored macro value (Set/Replace macro in level).
how should this work when a host is a member of several groups ?
Maybe by introducing a new "primary" group for hosts. Macros in this group would take precedence.
Macros in all other groups would be processed in alphanumerical order, the last match would win.
FWIW, I wouldn't really need a primary group, the "last macro wins" solution would also be OK for me.