It seems that the Google Picker API does not offer a direct way to check for editor status, but you may find assistance from the Drive API.
After reviewing the Google Picker documentation, it appears that the picker uses PickerBuilder() with View objects to control file visibility. The DocsView subclass includes a setOwnedByMe() method to filter files owned by you, though it does not account for editor permissions.
Although View offers a setQuery() method that might seem useful for adding search queries, testing revealed that it utilizes Drive UI's advanced search syntax, which does not include an option to check for editor status. This method simply populates the existing search field in the picker.
An alternative approach involves using the selected file IDs from the picker's Response.DOCUMENTS, validating user editing permissions via files.get, and providing warnings for inaccessible files. Additionally, explore files.list for searching guidelines, including querying editor status with '[email protected]' in writers.
If exclusively displaying files based on editor access is crucial, consider developing an app solely utilizing the Drive API instead of relying on Google Picker. Since PickerBuilder() forms a dynamic connection to Drive, integrating files.list data into it poses challenges.