Issue Tracker can easily be sort by different types. Default sorting is “By Updated On”.
To sort click on sorting options drop down and select “By Severity”. It will sort items in following order
Default sorting order is “Descending”, If you click on the “Sorting icon ” Z–>A then the sorting will be reversed and now “Enhancements” will be shown first and Blocker at the end.
Following screen shot explains the options in more details.