I am trying to do the same thing. My data has the manager name and the agent name. When I select one manager, I would like the agent list to only populate for that manager.
I selected 'only relevant values' based off another posting but it still is not limiting the filtered list of agents.
I changed from the multiple values dropdown to the single value dropdown. This worked for me!
I am not sure if the filter cannot process where multiple values can be selected. It would be nice for me to select two managers and see a larger group of agents. If anyone knows another way to get that output, please let me know.
I looked at your sample workbook and I modified the filters a bit. It looked like the filter was applying a subset already (parent A and child 6). I removed an re-added the filters and made the parent option a single value drop down. You can see the 'all' as an option to view the entire data set. I also modified the filter to reflect 'only relevant values.' Tableau seems to default to the 'all values in database' option.
Hope this helps!
Filter - dependent filter.twbx 24.0 KB