In one of my projects, we built a directory largely based on this article with content created by Stacy Deere-Strole of Focal Point Solutions. Something we ran into was wanting to include multiple departments in our base search query (not refiners, as that only narrows our results instead of expanding them). We also wished to eliminate multiple results in the JobTitle property within the query text. While this is a simple solution, hopefully it will save you some trial and error in writing your search language.
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