Logic filtering on data connections

You can have a data connection and sometimes want to keep it high level such that it can be used in many WKFLs. However when you add the data connections to the form using an external data connection you may always want to have criteria A and (B or C). Currently this doesn't seem possible so you have to create a duplciate relationship data lookup ad the or filter conditionality there and then on the form's connection add the filter for A.