Hi,
Descriptor idof was a useful feature of BI Apps analytics to have a dashboard prompt that shows both code and description, while filtering only on the code.
This feature is currently not available in the semantic model of the FAW, therefore it is impossible to show in the filters both code and description of some fields. It's still unknown if Oracle will release this feature in next update.
We opened the SR: SR 3-34104003461 : descriptor idof in data visualization