I'm trying to hide a column but it belongs in the RowGroups area. Unfortunately, the Column Visibility is greyed out and disabled. I'd like to just hide the column but keep the grouping.
I found a similar question on SO but its solution did not work for me. Is there a workaround for this?
ssrs column visibility inside row groups
I've tried shifting some of the columns to the body area of the tablix, but then I can't merge cells vertically. I'm not sure what my options are.
In the image below, I'm trying to hide the first column but the Column Visibility option is disabled. 
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SSRS 2008 R2