In the example I posted, there is a single 'on exit macro', named 'Counties' that manages all the dropdown options.
For content controls, have a look at some of these examples:
Dependent Dropdown Content Controls
https://www.msofficeforums.com/word-...html#post77762
and, for multiple levels of dependency:
https://www.msofficeforums.com/word-...tml#post132696
Cascading Dropdown Content Controls
https://www.msofficeforums.com/word-...html#post94603
Dependent Text Content Controls
https://www.msofficeforums.com/word-...html#post46903
and, for different elements from a selected item to be output to different content controls, see:
https://www.msofficeforums.com/word-...tml#post120392
Dropdown Content Control Population from Excel
https://www.msofficeforums.com/word-...html#post46287
Creating and Tallying Mutually-exclusive Checkbox Content Controls
https://www.msofficeforums.com/word-...html#post33489
https://www.msofficeforums.com/word-...tml#post107008