Please note that as per the thread description, this soultion is not like Jack's post. His solution was to select the items that are available and deselect the items that are not.

My solution removes the items not available, so you will only see the items

I created a work around extension to address this issue.

http://www.telerik.com/community/code-library/winforms/gridview/radgridview---excel-filter-enhancement-winforms.aspx#2659374

It also includes some additional functionality like:
1. When the excel f

I agree with the previous comments.  Having all filter dropdowns display all possible values all the time, even when columns are filtered, is confusing and not user-friendly at all.  

This functionality is very important for users who are used to make filters on multiple columns, I suggest making this functionality thanks

Many users are used to the filtering in Excel and are confused when the grid displays all the values instead of the limited(filtered) set. It is also hard to filter the 2nd or 3rd column when dealing with a large set of values with high entropy

In my opinion, chaining filters would be a great feature and would contribute to the user experience of data organisation and analysis.