Tibco Spotfire 7.5 - Remove round brackets containing field name of hierarchy column in rows of graphical table

Hi all, 

I have graphical table having a Hierachy column on Rows. 

When user move from one level to another the header of hierachy concatenate the name of level-filed between round brackets. 

Is there a way to remove the name of level-filed between round brackets?

Customer doesn't what to remove completely di property Row header name.