How to find dimension with more than 65,536 categories

[bobznkazoo]

I received the following error today in one of our cube builds:
(TR1901) PDS-PPE-0130 The number of children or parents of a category cannot exceed 65,536. (Drill) in \\UNC\Path\To\CubeName.mdc.

Evidently, I need to Clean House for a Dimension but I'm not sure how to find the dimension causing the problem.  How exactly do you use the Dimension Counts to find the dimension with the excessive categories?  For example I have these levels and counts within 2 drill-downs in a dimension:
    Product Group (192004)
Product Grp (24)  |   Product Grp (24)
Brand (96)          |
Model (6212)       |   Product Name (114)
Part Num (11422) |
        Unique Key (174148)

I'm not certain "drill-downs" is the correct term.
With counts such as those, how would one know where to look for a category with > 65,536 sub-categories.
Is there a better way to find the culprit Parent category?