Hi
Thanks for the sample :)
I think I have realised where the problem is as it still does not work for me. I placed the secondary datasource on the canvas within a repeating table. Then created a rule to hide some rows based on other fields on the form.
So now when I try to Filter for the difference on the main datasource, If I was to select the secondary datasource then this is the original data and not filtered.
So I think the main datasource needs to filter the data on the actual form, not the original data source, however this is derived (linked) directly from the secondary datasource. Perhaps these need to be different controls so I can pick them up when I attempt to filter the main datasource?
Hope that makes sense?
Thanks again