By default, when creating new transformations, the result is a new column. However, you can edit a column's values directly with this transformation. It allows you to perform transformations on an existing column using the formulas available within Wrangler.
Click the Search icon and use the Search bar to find 'Edit with formula'
You can now edit single or multiple columns using a formula defined here
You can also use Group by and Sort by options for your formula.