The narrow results feature allows you to remove unexplained transactions on an imported statement outside of a defined date range.
Navigate to Money > Bank accounts.
Click on the Explain link beside the imported bank account that you would like to narrow the results of.
Click on the Narrow Results link at the top of the statement.
Select a minimum and maximum date - any unexplained transactions outside of this date range will be deleted.
No explained transactions are lost despite appearing inside the date range specified.
Click on the Narrow Results button to process.