Showing different field layouts for entries within the same structure
The only way to do this is to create multiple entry types for your structure section.
Each entry type has its own field layout (can have different fields from the other entry types in that section).
Sadly, it's not possible to restrict entry types to a particular level in a structure – i.e. if you create &quot;Landing Page&quot; and &quot;Sub Page&quot; entry types, there's no way in Craft to make sure that the level 1 and level 2 entries actually use those entry types, according to their level. So, ideally you should a) make sure whoever edits the content in that section makes sure that they should be careful to use particular entry types for particular structure levels, and b) design and create templates that are flexible enough to work even if, for example, somebody publishes a &quot;Sub Page&quot; entry at level 1.
Most likely, you should change your current templating setup with something like this, if you go down this route.