Once you have created a rubric or grading form, it will be available to you in all the modules you are enrolled on via the Rubric Manager.
If you want to share a rubric with colleagues, you can export your rubric or grading form from the Rubric Manager as an rbc file.
In the same way, if you want to use a rubric or grading form which belongs to someone else, they can export it, share it with you, and you can import it into your Rubric Manager.