Create Authorization Object Field behaving like ACTVT

Dear Gurus,

I am currently trying to create authorization object field which should behave like ACTVT. That means when I click to maintain the field, the following window shows up, I can only select some of the values but not inputing free text:

I tried to create authorization object field even directly using the data element from ACTVT (ACTIV_AUTH):

but it still shows window like following (free text input, but not check box):

When I click the search help (F4) button, then I get the following window:

My question is, it it possible to let the field behave eactly like ACTVT? Is it hard coded or I missed something here?

Thanks a lot!