Start with a 5.0 instance.

Create host, and on that host add 2 macros:

Build an item, trigger and make an action based on that trigger.

Action:

Force the trigger to go into the problem state, and see what's going on in the event details:

This can be confirmed by checking that log.log file:

[root@zbx50 zabbix]# cat log.log  
The hidden macro: hidden and the clear: clear

Now build the same setup in a 5.4 instance (or upgrade your 5.0), and check the event details:

When opening that log file:

[root@zbx54 zabbix]# cat log.log
The hidden macro: {} and the clear: {}

Expected: The same behaviour as 5.0 since hostmacros aren't that strange to use in your actions.