The issue is user must cancel the Group before filtering.
Please refer the picture from attachment
3 Answers, 1 is accepted
answered on 22 Jun 2012, 12:37 PM
Thank you for this question. Currently, it is not possible to add custom buttons inside group field elements and RadGridView does not support fildering by groups. However, this is an interesting scenario and I added it in our issue tracking system as a feature request. I updated also your Telerik points.
You can still show the column by which RadGridView is grouped. This will allow you to filter by it. In order to show the column, you should set the ShowGroupedColumns property to true:
Does 2013 Q1 version provide feature of Filtering on Groups (RADGRIDVIEW for Winforms?)
answered on 01 Apr 2013, 01:21 PM
RadGridView produces groups by using group descriptors that specify which field to use when applying the grouping operation. You can also apply filter descriptor on the same column. So, yes RadGridView supports filtering by grouped columns. RadGridView supports also custom grouping and you can specify your group condition with code. To do this you should handle the CustomGrouping event. Find further information about this feature in our online documentation.