It seems like order item filters apply if any order item meets the criteria. It would be great if there was an option to set these filters to evaluate criteria against all order items.
For example, I have a number of views set up to split up my open orders by order item category. This helps to speed up most aspects of our production line by grouping together orders that need to be handled in the same manner.
My ideal scenario is to have one view for each main product category, then an 'everything else' view which contains orders with multiple items from different categories and other less common products.
However, due to the way the order item filters work, the only way I can create a view that shows me orders with 1 or more item from the same category is to create a 'Category equals x' filter, followed by n number of filters specifying 'Category not equals y' for every single other category in the system. Without these 'not equals' filters, the view will show orders with mixed category products which defeats the point of streamlining the view.
This approach is confusing, over-the-top (I end up with about 12 order item filters per view just to separate categories) and easy to get wrong, plus will be a nightmare if I ever want to add a new category or change the name of any existing category. A simple 'apply to all order items' checkbox would be amazing and so much more flexible!
Another use-case for this: stock level filters to make sure all items in an order are in stock.
Bonus points available if you fancy adding support for accessing order item extended properties in these filters!