ArcGIS Online Web App builder offers a query widget to select by attributes. The query widget offers the option of displaying the results as an operational layer on the map. The enhancement would be to make this "operational layer" available to the attribute table widget. The attribute table widget appears only to support interactive selections at this time. Having the query results visible in the attribute table widget would allow a user to view, sort and export the records they have already selected via the query widget. The attribute table widget appears to only allow one to filter by extent, and to select rows interactively.