How to put a dropdown in a tableview header??

I´m trying to replace a column title by a dropdown.

Iterators provide a method to define columns in a tableview (GET_COLUMN_DEFINITIONS), the most important parameter p_column_definitions has a component that looks interesting: DISPLAY_BEE.

I though I could send a dropdown in that BEE, but it ain´t rendering it.

Has anyone used this??