no, there is not a tutorial for this
first create the recordset to return all products
You would need to set the links to pass the letter as a URL variable:
page.php?sort=a
go to the bindings panel, click the plus button and add a new url variable binding named "sort"
then use data assist search. open the server behaviors panel and click the plus button, select WebAssist -> DataAssist -> dataAssist Search
for the trigger, click the lightning bolt icon and select the sort url variable.
add a new criteria, select the product name column, use the Begins With comparison.
in the filter type, select Key Word, for the filter value click the lightning bolt icon and select the sort url variable.