Add "Unselect All" on Datatable filter column

Hi everyone, I have a datatable with some columns and I need to add the option “Unselect All” in a multicomboFilter on one of these columns.
But I saw that we only have the option selectAll that show the “Select All” option and when we click then we will have the “Unselect All” option.
I would have the “Unselect All” option fixed by default on the top.

Can anyone helps me?
Thank you in advance.