For Dependent Dropdown Content Controls, see:
https://www.msofficeforums.com/word-...html#post77762
and, for multiple levels of dependency:
https://www.msofficeforums.com/word-...tml#post132696
For Cascading Dropdown Content Controls, see:
https://www.msofficeforums.com/word-...html#post94603
For Dependent Text Content Controls, see:
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