I have a QuickSight dashboard with multiple visuals, all driven by a buId parameter. A custom filter, linked to this parameter, is controlled via a filter control. Currently, when the buId parameter is passed via the URL (e.g., /?buid=abcdef), the dashboard correctly filters data based on the provided buId value (abcdef).

I've added a second parameter, BU ID List, populated with all available buId values (sourced from a dataset) and presented as a dropdown control.

The desired behavior is conditional display of these controls:

If the buId parameter is present in the embedding URL, the existing BU ID control should be displayed. If the buId parameter is not present in the embedding URL, the BU ID List control should be displayed. Furthermore, the selected value(s) from the BU ID List dropdown should be applied to the existing buId filter, effectively replicating the filtering functionality previously driven by the URL parameter. How can I implement this conditional control display and ensure the BU ID List selection correctly filters the data when the buId parameter is absent from the URL?

I have tried multiple things but not able to acheive this, not sure what I am missing here. I just want that condition of setting control parameter based on the query parameter from URL.