If I hard code some Author names to populate the drop down box (i.e. just type them in the settings dialogue) it works fine. But that is a nasty hack that is not really scalable as we would keep on having to edit the page definition every time we got a new author, rather than just upload the data. Things like this should be data driven, not coded.
Yes you are fully right! You recognized the right way!
(equals, greater than, contains, beytween x and y, etc., etc).
All of these stuff is already given.
I would say, take the offer of Code-Queen-Nayeli (CQN) and take a look at her examples/videos, she has good explained stuff, which could help you understand things better.
Also you can take a look at my site, where i also have some examples created directly from user-questions in this forum.
https://russian-dima.wixsite.com/meinewebsite
Look for “Test-Filter” and you will find an example, which could also help you understanding all the processes a little bit better.
https://russian-dima.wixsite.com/meinewebsite/blank-3