The FileExplorer could indeed benefit hugely from an advanced search/filtering implementation. In that respect I would ask you for more feedback on how do you imagine this feature?
First of all do you imagine this as an improvement over the existing filtering UI, where the filtering would search within the children of the current directory and would list the results in an hierarchical manner?
Do you consider this functionality a separate dialog with search options defined there and the results listed in the current directory listing?
Or this could be a separate view along with the grid/details and thumbnails view, where the filtered results are listed in a specific manner?
Please, share your thoughts on this functionality.