Interactive Categorical Data Dashboard Development

Hello, can someone please help with the following? I have a interactive dashboard (see code and dataframe attached) that shows the average revenue, sum of quantity and the median freight (y-axis) for different cities with the "Order Date" on the x-axis. I would like to expand this dashboard with the following:

I would like to add a dropdown with the different "ShipMode", so that I can filter by the "ShipperCity" AND "ShipMode". I would also need to switch between the "OrderDate", "ShipDate" and "InvoiceDate" on the x-axis.

Thank you very much!
Jurgen