Add a dependent to the listings with Top Level.

There is a custom solution to this problem, Custom solutions do come with complexity, so please do an impact analysis before moving forward with this solution

Solution:

Currently, you have a Flat list say 'list flat' which has a Top level enabled, due to which when this list is being used as a line item format you see top level selectable.

To solve this issue:

1. create a list 'list parent' and put it as parent to 'list flat'. Create a list item in 'list parent' as "All" and map all child items in 'list flat' with parent member as 'All'

2. Remove top level from 'list flat' and apply top level for 'list parent'.

3. Create 2 line items like this:

, the Line Item Dropdown format can be updated with the dependent dropdown setting as shown below:

4. Select 'All' under Mapper line item. 

Thanks

Aditya Shubham