H5P Interactives can be created from multiple locations within D2L from both the system-level and the course-level.
The best way to share a H5P interactive with another instructor is to Clone the interactive and then Assign Owner to the other instructor. Cloning Interactives creates a copy of the H5P Interactive and edits made to cloned content will not impact the original interactive.
How to create interactives in H5P.
How to edit interactives.