Set the tabpage , auto declaration property to Yes and in run method at end use setFocus on that tabpage
This tabpage uses inventTable2 datasource, so you need to filter the records in that data source.
for that you need to find the caller data source that is purchTable. which already exists in \Forms\PurchQuickQuote\Methods\doApply method . so make that purchTable variable as global and move the code to init method purchTable = element.args().record();
override the executeQuery method of the inventTable2 data source and apply the range and value