It's a known bug of this old version. The problem is solved for now.
If you edited your views through the Hikashop editor, customizations are saved and upgrading should not affect it.
However, if you are afraid about this upgrade, you can also try to download the last version of Hikashop get the file filter.php in back/classes and try to use it instead of your current filter.php (administrator\components\com_hikashop\classes). Success is not guaranteed since the component evolved a lot but it may works.
BE CAREFUL! In order to avoid any problem, I suggest you to make a copy of the old file if you want to try the file switching.
Same thing if you want to upgrade, make a save of your whole website to avoid any disappointment.