The form designer is displayed in the right pane. The topics and feature classes are displayed in the form explorer.
The house number is displayed instead of the FID. The Detail ListFilter will not work in this special case, so do not use it.
Detail Control = FID_LOCATION = name of the combo box
Master Table = LM_STREET
Master Attribute = FID
Detail Attribute = FID_STREET
Display attributes = NAME (attribute with street name)
Orderby = NAME (sorts by street name)
Detail Control = MASTERBOX1 (the above Street box)
Master Table = LM_DISTRICT
Master Attribute = FID
Detail Attribute = FID_DISTRICT
Display attributes = NAME (attribute with name of district)
Orderby = Name (sorts by district names).
Detail Control = MASTERBOX2 (the above District box)
Master Table = LM_CITY
Master Attribute = FID
Detail Attribute = FID_CITY
Display attributes = NAME (attribute with the city name)
Orderby = Name (sorts by city names)
If SQL errors occur, check the settings of the above steps. Also, check to be certain that the indices of the attributes you have used are set up correctly.
Tip: To optimize the speed, check whether you have set indexes on the related attributes.