The FS25 Fashion concept's landscape brushes automatically expand:
A Farming Simulator 25 utility patch called Ground Type Auto Mapper is designed to recognize and register Combined Layers as complete landscape brushes automatically.
Numerous custom and DLC FS25 maps make use of dozens of composite layers that are not shown as selectable brushes in the landscape editor but are physically present in the map and used by the engine. Usually, in order to activate them, the XML map files must be manually edited, which is inconvenient.
This issue is resolved by Ground Type Auto Mapper, which fully automatically adds every composite layer that is accessible to the building menu.

Thanks to BMProd