Hello ,
I would suggest that instead of using the Provider/Consumer web part connections, try this using session variables to filter employess by the selected manager instead. In qSelector, you need to provide a Session Name and enable Refresh Page When Selection Changed checkbox. In qListView, you can create a CAML filter condition that filters the rows based on the Session Name you gave to qSelector.
Unfortunately we do not yet support rendering unique values in a qSelector that is configured to a list which contains duplicate values for the display column. As a workaround, you could create a custom list that holds the unique names of all the managers, and configure qSelector to this custom list, so that you do not see duplicate options in the dropdown.
Thanks,
Yuan