Please see the key concepts of the heap walker for an explanation of retained size.
Not all dominated objects are directly referenced by their dominators. For example, consider the references in the following figure:
Object A dominates objects B1 and B2, it does not have a direct reference to object C. Both B1 and B2 reference C. Neither B1 nor B2 dominates C, but A does. In this case, B1, B2 and C are listed as direct children of A in the dominator tree, and C will not be listed a child of B1 and B2. For B1 and B2, the field names in A by which they are held are displayed. For C, [transitive reference] is displayed on the reference node.
At the left side of each reference node in this tree, a percentage bar shows how many percent of the retained size of the top-level object heap are still retained by the target object. The numbers will decrease as you drill down further into the tree. In the view settings, you can change the percentage base to the total heap size.
The dominator tree has a built-in cutoff that eliminates all objects that have a retained size that
is lower than 0.5% of the retained size of the parent object. This is to avoid excessively long lists of small dominated objects
that distract from the important objects. If such a cutoff has been performed, a
cutoff child node will be shown that notifies you about
the number of objects that are not shown on this level, their total retained size and the maximum retained size
of the single objects.
A new object set will be created that contains only the instances of the selected objects. After your selection, the view helper dialog will assist you in choosing the appropriate view for the new object set.