i have tried :
IN Custom CSS:
.hidden_ColoumnHeader * .sapzencrosstab-DimensionHeaderArea .sapzencrosstab-HeaderCellDefault,
.hidden_ColoumnHeader * .sapzencrosstab-ColumnHeaderArea .sapzencrosstab-HeaderCellDefault
{
visibility: hidden;
}
In CSS Class of the Crosstab_2:
.hidden_ColoumnHeader *
also
.hidden_ColoumnHeader
its not working.