I am not studying the book so, my apologies, that I cannot direct you to any part of the book that might help you.
However, firstly you will need to change your label control to a textbox control so that you can get the events that you need to code later.
Secondly, what you need to do to get your subforms to work is to change the record source of each subform to a query. Within each query of the subforms you to need to set the selection criteria for one or more of your fields to Forms!<FormName>!<ControlName> replacing FormName and ControlName with the names of your own parent form and textbox control name.
Finally, you need to code one of the textbox events to ReQuery each of your subforms based on the current criteria that has been entered in the textbox using <SubFormName>.requery. It is typically the AfterUpdate event that is coded to requery the subforms but you may need to change this to accommodate what you are doing. i.e. using the OnChange event?
Hope this helps.