in
custom\Extension\modules\Opportunities\Ext\Vardefs\sugarfield_created_by.php
I defined:
$dictionary['Opportunity']['fields']['created_by']['reportable']=true;
in order to use 'created_by' as a filter in reports.
Still, created_by does not appear in the list of possible filters.
What's more, it doesn't even appear in Studio's field overview.
There is no entry in fields_meta_data for that field which could possibliy overwrite it.
Refers to Sugar 7.5.0.1