For your filtered control (in my case it was the MSLB), you'l need to apply to filter to that data. The current should be (sort of) implied since its within the context of the repeating control. To summarize, here is what you need to do:
- In the filtered control, go to control properties
- Select choice from a external source
- Select the data source you are pulling your data from
- Open up the entries dialog and select the repeating node that contains all of your data
- Click on Filter Data on this same dialog
- Add a filter -> something like columnA is equal to dropdownValue (not sure what your filter is exactly)
- OK all of the dialogs
The setup is very similar to what I have in my sample that I attached earlier. The major difference is the 3rd bullet point where I'm pulling in data from a SP list instead of an XML file. Hope this helps!