Hi again!
There is no option to do that, unfortunately product variations are stored as separate post objects, however I might have found a possible solution for you.
After some experimenting I was able to come up with this code:
You can put this code to the functions.php file in your active theme directory. It locates product variations from the reuslts and collect their product IDs. Then removes the parents from the list if it’s present – so only variations are left.
This is the closest I could get, I hope it’s something you needed.