You can use the above format to show the top 5 values in the chart and the rest bucketed as others, if you do not want to show Others, just do not enter the else condition as 'Others' (also, you will have to supress nulls on this calculated dimension.
Some of the demos have a link (DOWNLOAD . QVW) to download the .qvw file. You can then save them to your hard drive and view at your leisure. Some demos do not have this link, and can only be viewed in your browser.