To create a new transform, simply right-click the Tools > Transforms node and create the desired type of transform. A new transform node of the selected type will appear in the tree under the Tools > Transforms node. The default name of the transform will be based on its type. However, renaming the transform is possible.
You can edit the properties of the new transform to suit your needs. The new transform can now be used in any displayer, and will appear in the list of available transforms in the Transform property of all displayers.
Transforms are shared, so changing the properties of a transform will appropriately change every displayer using that transform. For example, consider a scene with a part displayer and a scalar displayer both using a graphics symmetric repeat. If you change the symmetry plane definition in the graphics symmetric repeat, then both the part displayer and scalar displayer will update and change the scene accordingly.