I would assume that you are using and external ECM server and not the embedded ECM that comes along with IBM BPM/BAW.
Looking at the problem, I would approach the debugging in the following order;
- Use a relevant ECM browser (ACCE in case of Filenet) to check if the
documents have a property that holds the value for the instanceID.
Because, by default external ECM servers don't have such a document
property.
- If the document has such a property, then use that in the
"WHERE" clause of the query. If it doesn't then talk to whoever
maintains the ECM environment to create such a property and make
sure that is set properly (to the correct instanceId) for the
documents.
Another solution if you have access to it can be using the "BPM Document List" and "BPM File Uploader" which has the feature (as a configuration option) to associate documents with the current process instance.