how to add a dropdown menu into Third Party > List - by: Serdar

Hi All

i added a New attribute under Complementary attributes (thirdparty) in Third Party modul as Checkbox from table.

i added a table to DB and it works with New third party so i can see this opition in Third Party > List

but i need to select this opition as dropdown menu in List. It works as a searcbox now.

Ty

Serdar