When you browse data and uses the filter, the latter version of sqldeveloper (3.2) did help you and suggested a column-name or names (like a kind of baloon-help) from which you could choose.
This doesn't work any longer, now you have to type the whole column-name ( and spell it correctly).
This is intentional. Many folks were not fans of the popup suggestions as it got in their way while they were trying to type.
Hit ctrl+spacebar to activate the help. This is the same keystroke to invoke the code insight feature in the worksheet when writing queries.