Hide Dimension Hierarchy if levels do not contain any data

I have a hierarchy in a dimension that does not contain data for specific roles.  For example dimension Dim1 has a hierarchy H1 with levels aaa and bbb.  When each level in H1 does not have data, and the data is unknown, I do not want the user to be able to select H1 in the browser.

Does anyone know how I can hide the hierarchy based on what data is in the hierarchy?

Thanks,

Steve