Subitems should have the same columns as the parent item but how?

[Bella]

I tried to use “Convert” for subitems so that they will have the same columns as the parent item but after doing it, I checked and saw that the columns from the “Convert” process that i did is messy. The columns of the subitems are not arranged like the columns in the parent item. Is there any other way to do it? Hope you can help. Thanks!