While not overtly necessary, it is incredibly useful to create “Layers”, basically folders, for your map. This helps with organization, especially if you have many items you’re working with.

To begin, access your World Outliner panel:

By default, you will have pre-existing layers, Constructions, Lighting, Terrains, and Triggers. You can add more if you see fit.

For my personal preference, I generally make a Foliage layer, and add all bushes and trees to this. When expanded, you can see the following:

I usually add a Rocks layer as well, and then depending on if I have a structure, I will make a related Structure layer. This is all personal preference, and a case by case basis, but it helps to keep yourself organized. You can get as specific as you want, if you have a House layer, you can add Layers for the Bedroom, Bathroom, etc.

One perk about using Layers is the ability to select everything within it. This is helpful if you need to mass delete, or re-arrange items. To do this, right click on your desired Layer, and choose Select Children:

After “Select Children”, every item within this Layer will be selected:

As stated previously, you can delete all items here by the Del key, or re-arrange them.

For example, these foliage items have been moved directly into the main structure:

Note: If the layer has a plethora of items, you may experience lag when moving items. Proceed with caution, and don’t be too hasty.

Additionally, if you wish, you can “nest” layers with a layer. So a folder within a subfolder. To do this, right click on your desired layer, and choose Add New Layer:

From here, you can rename the layer by right clicking, if you so choose.

And that’s all!