Hi @Sudharshan T ,

I solved it by replacing the default Wijmo “Filter by Value” popup with a custom single-select UI, while still using the built-in OutSystems Data Grid filtering logic.

Trying to force the default checkbox filter into single-select was unreliable, so instead I built a custom searchable list with radio-style selection and Apply/Clear/Cancel actions.

The key part was generating the values correctly: for each column, the list is built from the full dataset but filtered by the other active column filters (excluding the current one). This keeps the options valid, similar to Excel behavior.

I also had to handle nested bindings (like Entity.Attribute) and resolve the real column from the event, since the filter event returns a ColumnGroup.

Overall, the stable solution was not to modify the default value filter, but to replace its UI while keeping the underlying filter logic.

Result:

The CSS and JS are quite large, so including them here would make the post hard to follow. You can check the full implementation in the attached OML, and feel free to adjust the CSS classes and styling as needed.

@Sudharshan T : Similar implementation of @Mihai Melencu but with dropdown.

This is achieved using the attached javaScript. Call the same in Onready or DatagridOninitialise with DataGrid Id. Steps involved are 1) Intercepting the click 2) Identify the click 3) load the unique values 4) Show the custom popup 5) Apply the filter.   ( Please note this is AI generate code and use it with caution )

Thanks for your inputs @Mihai Melencu and @Siya . It works