Purchase order tool: Create sub products from options

I am using purchase order form. I have added Quantity and sizes field. But is it possible customer can select multiple sizes and quantity for the same product?

For example. if I want to buy Black Logo Tee Shirt, one S, one M, one L?

Yes its possible. First you need to enable sub products from options inside the size option for each product you have listed.

For example:

Then hit the green button "Save option" and then the other green button "Save product"

And it should look like this: