ComboBox that allows free text

I know you can set a ComboBox to allow new items where the user hits enter and the new item appears in the set of results. However, is it possible to make the ComboBox allow the user to set a value without having it appear in the set of results?

Essentially I’m looking to have a component that is like a combination of a text input field and a ComboBox where the user can select a pre-defined value or type in a value of their own without it adding to the set of results.