1. Select few items in Row labels field, using the Shift or Ctrl keys
2. Right click, select Filter -> Keep Only Selected Items or Hide Selected Items.

Or

1. Select a cell in a Row Labels filed.
2. In Row Labels, click the Arrow symbol (the filter arrow?) to open the dropdown list and cancel the selection of the item(s) you wish to hide.



The filter symbol replaces the Arrow symbol when hiding item(s).