Files App 0.3.0 now includes the option to filter by IPTC fields. There is a new config option
filter_props, by default set to 'name, filetype, mime, features, title', whereas "title" is the IPTC title (objectName). You can also includes any of the following IPTC properties in filter_props:
headline,
description,
creator,
credit,
copyright,
keywords,
city,
sub-location,
province-state.
Keep in mind, additional IPTC filter_props should be assigned with caution. If you for example assign + 'keywords' and 'description', filter will trigger on ANY phrase included in an images keywords or description, which may contain a lot of words and even long sentences. Furthermore, additional filter properties will slow down filtering.