When comparing and contrasting the similarities and differences between the filters of Categories and Value Filter: 'File Folder', the latter is more evolved in that there are file counts for each folder and also, the text-entry-option for this filter does what would be expected for, "Enter a filter expression".
On the other hand, looking at the categories filter with "Show only categories in scope" active, there aren't any file counts, and I'm wondering if this could be added? Also, here, "Enter a filter expression" is misleading because it doesn't filter; It just skips around the list to the next occurrence of the search-term, and I'm here hoping that this text-entry-field could be made to do what is says it does.
Finally, although not as important as the above outlined points, it would be very handy (IMO) if the text-entry-filtering for both of these filters could act on alternate search terms - For instance, Season 3|Season 5 narrowing the search results to items matching only either "Season 3" or "Season 5".
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