To build successive subsets and narrow your data selection progressively:
You can reset, or undo, the most recent subsetting action for a data set. Note that you can do this only one time, and only to the most recent subset.
Scroll to the Subset History panel at the bottom of the page and click Undo in the last row of the list of successive subsets.
The last subset is removed, and the previous subset is available for downloading, further subsetting, or analysis.
You can remove all subsetting activity and restore data to the original set.
Scroll to the Subset History panel at the bottom of the page and click Restart in the row labeled Initial State.
The data set is restored to the original condition, and is available for downloading, subsetting, or analysis.