why is the “Show in Filter Region” Greyed Out. need to use the document number as a filter.
SOLUTION:
As an alternate solution, use the Document Number/ID field instead.
To set Document Number as an available filter:
- Navigate to List > Search > Saved Searches
- Click Edit next to a Save Search
- Under the Available Filters tab, add the Document Number/ID field and check the Show in Filter Region checkbox
- Click Save

