Edit multiple selected rows at once

Hi all, I have a table with an editable column. I want users to be able to select multiple rows, then make a change(in my case it's just a multiselect dropdown) in any one of the selected rows, then any changes are applied to all selected rows. Note that this is before the changes are saved.

I am thinking I can probably get this working with a change cell event handler on the table and then run a script or custom query, but I'm unsure on how to refer to the event itself. As in, how can I reference the actual changes being made so I can update the other cells? Is this something that's possible?