As an example, lets use students on a bus:

 

The HTML view has a top division view of Bus records with fields: Bus_ID_Number, and Total_Count_Students_On_Bus.  

The bottom division has a view of Student records showing who was on a given Bus with fields: Bus_ ID_Number , and Student_Name.

My goal is to enable users (public or Zoho) to filter the HTML view so that each division is filtered for the same Bus_Number and therefore presents in one concise view both a summary above and detail related to that summary below.

I could create a Bus_Number filter in the header of each division, but that would require two filter applications instead of one.  I very much would prefer to allow my users to filter both divisions simultaneously with one action.

What is the best way to meet my goal?