The window for seeing who to share reports with should be larger, easier to select groups to share with, and easier to save.
When you toggle it open to share, you then only see one line of the groups to share with. If you can figure out how to scroll down a bit (with a mouse) to see more of the window you can select more than one group, but then you have to click back into the groups previously selected to see the save button show up.
It's a tedious process if you just want to use the keyboard to navigate, and errors are easily made if you try to use the mouse. Then the extra click to try to get the save button to appear seems redundant. It should just be present on the screen/window the full time.