When I select an item on the second dropdown menu, the related item in
the first dwropdown menu will be selected
dependant dropdown menus
(not just ADDT ones) don´t work this way, as both menus have a sort of "master/slave" relation, where the first one
(the "master") passes some information to the second menu
(the "slave"), but - after passing the "dependant" array of information to the slave - is technically not aware of what option you selected in the 2nd menu.
What you´re looking for, is a sort of bi-directional data flow between two menus which may both act as "master" and "slave", and that´s something what ADDT´s
(and others, I have never seen that elsewhere) dependant menus can´t do.
Adobe Community Expert, Dreamweaver