I will take an example to explain what I would like to do

Let's imagine I have 2 datasources:
- "people" with a parameter "name starting with letter..."
- "their children age"
The first datasource is a stored procedure, retrieving people names (starting with "X" for example) + the name of their children.
The second datasource retrieves the age of the children found in by the first query.
Of course, I don't want my second datasource to search for the age of all the people, but only of the children found by the first query.
It's like giving the results of the first query as a parameter for the second query.
Is there a way to do that?
Thanks for your help!
Edit: I found this topic, which helps a bit. But why didn't you set the relation property of databand2 in your example? There is only a filter property.