Dotted fieldnames, how to create?

Hi all,

Not sure if this is the right place to ask...
I'm new to ElasticStack, and I'm trying to find documentation on how fieldnames are built.
When I look at Kibana Discover, I see fieldnames like host.name and system.auth.program.
I was able to successfuly add my custom logfile mylog.log, and my fieldnames defined in a grok filter are field1, field2.
I'm looking on how I can create a field like mylog.field1 and mylog.field2`

I'm not sure on what to search (and I'm ok reading documentation).
Can someone please point me to the right docs?

Thanks a lot!

Hi WimDH,
the term you looking for is nested fields.
It should work with putting a [mylog] in front of your fields in the GrokPattern.
Like

%{GREEDYDATA:[mylog]field1}

Regards,
Simon

That may work in a grok filter, but in a sprintf reference that would get an ambiguous field reference error. It would be better to use [mylog][field1].