There are several ways to do this:

• • Simply select a subsystem and tag all the cycles within the selected subsystems. High level cycles are tagged using one tag and low level cycles are tagged using another tag. Generally, high level cycles are of concern. You invoke the Tag Cycles menu item, by right clicking on the selected subsystem or by invoking it from a menu item in Tools.
  • You can select a subsystem and generate a Project Report to find all cycles within a selected subsystem. In order to find all cycles in a project, simply select $root.
  • DSM Component (or Reachability or As Early As Possible or As Late As Possible) Partitioning will also identify cyclically connected subsystems. Chose a subsystem within which you want to see the circular dependencies. Expand it so you see all its children. Select the partition button on the tool bar (or right click and chose the partition menu item). All the dependencies above the diagonal are guaranteed to be part of circular dependencies.