How to add functional item to s:DropDownList?

Question

So I have a s:DropDownList with data from service. When an Item from recived list is selected I perform some action (lets call it Action A) I want to add an item visible in list so that when user selects that one item I'll perform another action (lets call it Action B).

Toda when I use such code to fill my list:

        <s:DropDownList >
            <s:AsyncListView list="{getDataResult.lastResult}"/>
        </s:DropDownList>

What I shall add to it?

So how to add functional item to s:DropDownList?