We have a UX situation in an enterprise site for a very large customer that has a very deep product list for a support site. We need to indicate that the product field is required, but deeply nested. Some menus go as deep as six levels! The user is required to choose from a product deep within that hierarchy.
We're currently making the menu a bit simpler by using an expand/collapse at the top level. Then, when the user selects an item from the menu, we expand to the next level, etc. But it is not clear to the user that it is required for them select a field that is six levels deep. Many (most) users miss that it is required and get frustrated with the form submission, continually having to go back to select a deeper category. Any ideas on how to indicate that a deeply nested product is REQUIRED?
This example shows only two levels:
Imagine in this case that one of those sub items are required. Now, extrapolate that even deeper in the hierarchy.
And unfortunately, there is no chance for restructuring their product catalog to make it more flat.
EDIT: for clarity