Good Question! I am still looking for a way to configure my dependencies.... I have a similar structure.... If you find a way, please share it. I will do the same.
Good morning everyone,
While creating dependencies for Child devices, you must nest the devices in a group. Your child parent device/group cannot be in the group you are creating! After you have completed that, go to settings->manage dependencies-> add new dependency from there you select the parent object. Click Next. Next you select the child object. On the left side under show only, change it from Nodes to Groups. Then select the group you created. Continue through by clicking next. You can change the name of the dependency and finish there.
Please let me know if you have any further questions.
On a side note. You can still add that parent to another group as a child. However if the first parent is marked as unavailable not down due to a dependency, all lower dependencies will not function properly.