thank You very much for Your answer and Your example. It works very well.
I just have a question about Your example:
In Your example You use AutoGenerateHierarchy = true and You bind the data of the grid to a data source. In Your case the excel like filtering works automatically.
In my case I use a List<> of objects and each one has a sub object List<> (my data in memory). The hierarchy is generated perfectly but the Excel like filters are not generated.
I thought that in general that the excel like filtering does not work for child elements when the data is filled by a data source and the hierarchy is generated automatically because of the lazy load of the data (from database or from object list). But Your example shows that it can work!
The question is what are the prerequisites needed or what can I do to make the automatic filtering work (e.g. use another object in memory)?
Thank You very much!