I can now confirm that by signing up on the Zack's web site for a free membership, I am now able to sort the list of individual stocks that make up a specific ETF or Mutual Find by percentage gain in the past 4 weeks, in the past 3 months, and year to date.
First I had to become a Zack's web site member (at no cost). This is nothing more than giving them your email address, and creating a password. Doing this gave me access to other features on the website I had not seen before.