The concept of demoting changes was discussed in Demote: Moving Elements Out of a Stream where it was noted that AccuRev supports the ability to demote by file, by transaction, and by issue. If you promote by issue, you have the option to demote by issue if you want to back out specific sets of changes.
After you select a destination stream or workspace and click OK, the changes associated with the issue(s) are no longer present in the parent stream but are now active in the default group of the destination stream or workspace you specified.
If you right-click a file in issue 10, select History > Browse Versions from the context menu, and hover over the demoted version, the tool tip confirms the demotion: