Hello Basel Nimer,
You can modify the default filtering context menu by handling the ContextMenuOpening event:
Depending on your scenario, you also may need to prevent the user from entering a value in the filtering cell:
sender, GridViewCellCancelEventArgs e)
Last, but not least, you should customize the filtering behavior on Click of the custom filerting menu items. To do this, you need to handle the CustomFiltering event. I am attaching a sample project that demonstrates the full approach.
If you need additional assistance, feel free to contact me.
the Telerik team
Do you want to have your say when we set our development plans? Do you want to know when a feature you care about is added or when a bug fixed? Explore the Telerik Public Issue Tracking
system and vote to affect the priority of the items.