how to use drop down filter and how to add filter and attributes
The dropdown you are using there is not a filter in your case. It is used to change an attribute from an entity.
If you want to add a dropdown filter to filter your list view your best option would be:
Use a Template Grid widget to show your list of items instead of a List View. This way you can add a dropdown as filter to your list.
Add your data source the same way as in the List View you currently have.
Make sure to fill the contents of the template grid by clicking YES on the question 'Do you want to automatically fill the contents of the template grid?’.
Set the amount of columns of the Template Grid to 1 column.
Remove all the unnecessary search filters and content in the template grid, and keep the filters you want. The filters should include the dropdown filter you wanted. If not, add it manually by right-clicking on the filters and clicking 'Add search field’ > 'Drop-down’
Hope this helps!
Assuming you are using DataGrid 2.0, you can drop the drop-down filter in the desired column’s widget area and set the values automatically using the ‘Automatic values’-option: