How to filter dropdown menus/lists?

How to filter dropdown menus/lists?

We have a dropdown list (Bike_Info) that we need to filter out.  The dropdown list (Bike_Info) pulls data from the “Bicycle Listings” Form (Bike_Listings) and displays the bike serial (Bike_Serial) of all the bicycle records.  We need it to filter out the list to only show Bike Serials with a Service Status (status) that are “online” and not display the bikes that are “in maintenance, checked out, etc.”

Is there a way to do this?

Thanks!