Allow mail merge ranges to access parent data Duplicate

Using RangeStart/RangeEnd can be useful to hide sections that are not needed in the output. But those sections are limited to the data contained in that specific object. I would be nice to access data in the parent object. Maybe something like {MERGEFIELD Parent:FieldName} or {MERGEFIELD RootObject:FieldName}

In my case 1 or 2 users are signing the final document. The signature area needs to include the date of the report. I have a subject object for each person. I can start a range for the cosigner but then I can't access any of the top level data for the report.