Has anyone found a solution to making a dropdown within a dropdown for the main nav menu?

I'm creating a new website for an organization that has 35+ pages of content and I need to create a dopdown menu within the main dropdown for the top menu navigation. I know SS7 doesn't support this so I'm looking for other workarounds or a custom code I can use?

Folder nesting  has come up before, and there is no change for this, folders cannot go into a folder. No workaround or code for that. You can make a folder simulate a folder inside of it, in a way. 

Change the text Medical, Dental Providers  and Leadership Team,  indent it with some dots or dashes to make it pop out as a "seperate" menu .  So it looks something like this:

Our Staff

.........Medical Providers

.........Dental Providers

..........Leadership Team