Thank you for your question.
The samples of localization XML files in the documentation article http://www.flexmonster.com/doc/localizing-component/ have been updated with the localization key names for “Click to drill down” and “Click to drill up” tooltips. They are the following:
<drillDown>Click to drill down</drillDown>
<drillUp>Click to drill up</drillUp>
Thank you Iryna.