As it stands now Open Orders filters can have single items of filtering. For example if I want to select all orders where Stock Level is Not Out-Of-Stock and Awaiting Stock it will not be possible as Awaiting Stock might include everything that is Not out-of-stock and the Not Out-Of-Stock will mutually include everything that is Awaiting Stock. Basically the filtering works as follows:
If the same field is selected multiple times it will be treated as OR operator in the selection, in the above example it would look like
StockLevel IS "Not Out-Of-Stock" OR StockLevel IS "Awaiting Stock"
If the different field is selected the operator is AND, for example if in the above example we include order status PAID, the selection criteria becomes
(StockLevel IS "Not Out-Of-Stock" OR StockLevel IS "Awaiting Stock") AND (Status IS "PAID")
Implement an ability to include lists of items in the selection criteria, so that within the same element the user can select multiple items with positive match or a negative. See screenshot for more details