You can achive that by creating a helper entity connected to your entity or to some other existing association, depending on the scenario.
That helper entity can be non persistant and can or cannot have any attribute, and you can define the search field for example in a dataview with a nanoflow as data source, which will change that helper entity and will reflect on the datagrid2 that you should put inside the dataview mentioned above.
Hope it helps,
Thanks for your response. I believe using the default value in the dropdown search function within DataGrid2 would be the best approach. I ve tried it, but it didn't work. I dont want to add a new temporary entity or attribute because I think this should be done using datagrid2 functions.