Hi Jooo
I am almost certain that state is the filter that you can check or uncheck in the solver configuration block when connecting 1D with 3D component. Unfortunately your attached model misses all the CAD files so it doesn't run or compile, so I cannot confirm it.
solver configuration block:
You had the right idea on how to setup the kinematic connection between Simscape 1D Motor and 3d Multibody joint, but there is a more refined variant of your method that may remove the need to filter between 1D and 3D. Look up this package on the file Exchange:
There are really nice example and there is even a DC Motor model that you can apply to your rotational joint:
When you work on a project with multiple files such as with CAD files for Multibody, I recommend to setup and work within a Project. Projects allow you to relate all files with one another and export a working environment as a single Project Archive, that other user can easily open and work with.
Hope this all helps, good luck!
Vasco