Currently (since branch 3.5) you can select multiple items from the Autofilter dialog. However since Empty is a separate choice on the Autofilter menu, it is impossible to filter data based on a criteria such as (col1 = x OR col1 = empty) or a more complex filter such as (col1 = x OR col1 = empty) AND (col2 = y OR col2 = empty) This could be simply solved by adding the -Empty- option to the multiple selection dialog (as it is possible in Excel 2007 and newer) instead of (or in addition to) one of the menu items.
Created attachment 98419 [details] ODS spreadsheet with 3 Autofiltered columns Please see discussion about this issue in the comments of my answer to http://ask.libreoffice.org/en/question/26829/autofilter-usage/ The attached file allows to quickly test the case proposed by user jnnewton
This duplicate bug describes a solution which would be intuitive for the end user, especially those using Microsoft Excel. *** This bug has been marked as a duplicate of bug 44895 ***
*** This bug has been marked as a duplicate of bug 65505 ***