Under the Settings/search. There are often links and most often a side info box next to each setting in the back end of the SLP. Just hover over the settings if you do not see what they do.
Also make sure you have the discrete filter to just be Dropdown Discrete for the selector and assume you have set allow selector and address inPUT. It is difficult to advise you based on the various questions we have seen in the past. But that is where the setting is