We add a custom library select option to the patron search results datatable. We should really generalise this away from the patron-search includes so it could be used on other ajax driven datatables with the header row filters enabled. We should support both 'data-filter="libraries"' at the table heading line definition and 'filter: "libraries"' in the datatable column settings definition level.
This would be good to add to bug 33568 to improve consistency between different uses of datatables.. having a consistent filter between patron search results and items tables would be great.