Local/Sublayer
Layers can sublayer other layers, grafting multiple layer stacks together in order into one. Sublayering is in fact how Layer Stacks are made!
Order matters when sublayering.
To emphasize how order matters, given a Cube prim at path /Foo in layer_a.usd and a Sphere prim at path /Foo in layer_b.usd; when sublayering both in layer_c.usd, the final type of /Foo will depend solely on the order in which layer_a.usd and layer_b.usd are brought in.
Below we have three layers, a_cube.usd, a_sphere.usd and cube_and_sphere.usd
a_cube and a_sphere define a Cube and Sphere prim respectively. cube_and_sphere does not define either but sublayers both previous layers, essentially combining the two hierarchies into one defined in cube_and_sphere’s layer stack.
Sublayering grafts layers together at their roots! If you wish to combine layers at different levels of a hierarchy, use the reference composition arc