Ahh I’m afraid that at this time, there currently is no way to query multiple columns and/or multiple column values using the items_by_column_values method.
This is something our developers are working on though. Hopefully this feature will be released before the end of year, but it’s not set in stone.
Just to update, we do not support the ability to filter by multiple column values in a single column. We haven’t released the ability to filter by multiple columns just yet, but wanted to give you an update!