I would like to validate when i create a new list item that the metadata item selected is a specific item and not a top level category
for example in the above you should not be able to select People or Commercial as they are top level categories. But HR, reporting and summary should be able to be picked.
Whats the best way to do this. We currently have a custom content type in which we define this column but I cant see a way of doing this kind of check either via the UI or the fielddefinition.
My thoughts are that the best way to do this is via creating a new content type edit form which understands this validation but i was wondering if theres an easier way.