Conditional Dropdowns in Subforms

Conditional Dropdowns in Subforms

I created a form where the available values of some of the lookup fields were filtered based on selections made in other lookup fields. The filters work great if I access the form directly.  But, the filters don't work at all when the form is used as a subform.

Is it possible to filter lookup field values in subform dropdowns based on selections made in other lookup fields in the same row of a subform?