yiisoft/yii2 — pull request #5589 by mitalcoi (2014-10-16 08:41:57+00:00)
Title: Add ability to filter data in multiple dropdown for GridView

Now GridView could filter the data sent through the multiselect. Also added option to delay before sending data. Now user can select the values in multiselect (important for PJAX-update grid) without force reloading of page
Thanks to @maxsoad for the help