We will simply attach the geometry from the system "Cantilever Geometry" to the Modal Analysis System (Cantilever Modal). In order to attach the geometry, (left click) Geometry in the "Cantilever Geometry" project and drag it to Geometry in the "Cantilever Modal" project, as shown below.
Then release the left mouse button. You should now see that the geometries are shared as shown in the following image.