Many of the search boxes in Zabbix give suggested autocompletion, ie when searching for hosts.
The search box on the top-right of the Zabbix GUI also autocompletes when searching for hosts, but the text you are searching for has to match the start of the hostname.
Other search boxes match hosts, even if the text is not at the beginning of the hostname, just within it. (ie. in the Latest Data screen).
In the example attached, I have to search for "UK BE Access" to have matching results on the top-right search field. Searching for "access" alone does nothing.
One doesn't always know that the hostname starts with.
I have a feeling this was working with 2.2.x , but to be honest I can't remember and I don't have a test environment to test with. It would be nice if it could be fixed/implemented.