First, thanks to Nick who tried to help, and got me thinking. (If this were 'Apple Discussions' I would give you a star.)

IF YOU TRY THIS, MAKE SURE YOU ARE USING A SCRATCH EXTRA COPY OF YOUR DRAWING, THAT YOU CAN COMPLETELY RUIN JUST IN CASE SOMETHING GOES WRONG. MAKE BACK-UPS.

Let's say you have parent layer 'A' with sub-layers 123, 456, and 789.

-A
--123
--456
--789

First you must create new empty TOP Layers, 123NEW, 456NEW, 789NEW.

Hide everything except sub-layer '123'.

Then: Edit > Select All, (all the objects in sub-layer '123' turn red).

Window > Object Info. Look for 'Layer' and change it from '123' to '123NEW'. Click Apply.

Continue that process until all of the sub-layers have been moved to the NEW top layers.

I now had nothing in the parent layer 'A' and the sub-layers below it are empty also. All of those OLD sub-layers are now NEW Top Layers.

I then delete the now empty parent layer 'A'.

The above procedure may fall under the category of “everyone knows that” but I spent several days on this form seeking an answer, and could not find one. Maybe I wasn't asking the question properly.

I have been using CAD Programs for 30 years (but very intermittently). The lack of layer control in ViaCAD is a huge shortcoming in my mind.

As I understand the software now, I will NEVER have anything other than Top Layers. It's just too difficult to turn the children into parents.