Fold out

Use

As the FoldOut boolean value in the inspector is selected, it changes its value to show or not the objects that contains.

[CustomEditor(typeof(SampleScript))]
[CanEditMultipleObjects]
public class SampleScriptEditor : UnityEditor.Editor
{
    private bool _foldOut;
    private SerializedProperty _vector3;

    public void OnEnable()
    {
         _vector3 = serializedObject.FindProperty("vector3");
    }

    public override void OnInspectorGUI()
    {
        serializedObject.Update();
        _foldOut = CGFEditorUtilities.BuildFoldOut("Cube5", "Description", _foldOut);
        if(_foldOut)
        {
               CGFEditorUtilities.BuildVector3("Position", "Description", _vector3);
        }
        serializedObject.ApplyModifiedProperties();
    }
}