Same day price touch of upper and lower Bollinger Band

Here's a link explaining the Advanced Scan Workbench. You can build scans by selecting the things you need from the drop downs and then editing.

https://stockcharts.com/docs/doku.php?id=scans:advanced_scan_workbench

Links to scan writing tutorials are here:

https://stockcharts.com/docs/doku.php?id=scans:tutorials

It takes a little time to go through them, but they aren't too complicated and you'll probably get the idea pretty quickly.

Your scan might look like this:

[group is SP500]
and [high > Upper BB(20,2)]
and [low < Lower BB(20,2)]

That just says both the high and the low are outside the bands. But, it would would include situations where either the high or low, or both, were outside the bands yesterday also.

If you want hits only when high and low were both inside the bands yesterday, and both are beyond the bands today, you would use the cross above operator 'x':

[group is SP500]
and [high x Upper BB(20,2)]
and [Lower BB(20,2) x low]

Note that you have to change the order for the low crossover. 'x' means cross ABOVE, so you have to think of the Lower BB as crossing the low, instead of the more intuitive low crossing the BB.