this is not a trivial problem, there are many steps so I can't give you a step by step process to do it. I can give you a high-level strategy, but you will have to go through the process of learning how these tools work ( if you are not already familiar with them ) and solving the unique detail of your specific problem.
Since you did not answer any of the questions in my post, I am going to assume my assumptions and assertions are correct, and you want to do it my way.
These are the key modules you would need:
Entity Reference View Widget
There will likely be other modules that you would need.
Build a paragragh.
- Score. Likely a text field or number field
- Student. Likely you want an entity reference to user, not the profile2. It can make you life a little easier, and you can always get the profile2 properties from the user.
I just realized, you want your entity reference to only list the OG members. This makes things more complex. You now need another module "entity reference view widget", I added to the list. I am not going to go into details for that module, only to say you need to create an entity reference view that is a list of OG members, likely using the contextual filter of NID from the course.
On your "course" content tyoe, add the paragragh field.
Now you need a new view of the course. It would be a table, first column would be the student ( OG member ), second would be the score field. You will need to build the relationship to the paragragh entity reference in views.
Actually, I just thought of a better approach, add a Paragragh to the student's profile2. It would be an entity reference to their courses.
The basic things still apply. This is a complicated problem, to be sure.
What you want to end up with is a table view where a teacher (I assume) will have a list of their students, showing the score ( showing zero if there is no other score ) in one column.
Here comes Rules. This is going to be tricky, and if you've never used rules, you will need to read a lot and try many settings.
You need to create a rules component. You need a component the has an Action ( either a Rule Set or Action ). It need to accept 3 parameters, a user ( student ), a node ( course ), and a string ( score ).
Actually building this is very complex, I don't know that the VBO can provide 2 values from the view object. You might either have to write a custom hook to provide it automatically or have the teacher enter either the NID ( course ) or UID ( student ).
What you want rules to then do is load the user, add a Paragragh reference to the user's profile that includes the course, and populate the score with the teacher provided value.
Then in you OG Member view, you need to add a Bulk Operation field. This part is easy.
For someone very familiar with these modules it could take a few hours to a few days depending on what problems they encounter, how well user input is handled.
I use Rules and VBO in a lot of custom management dashboards. It gives the site manager a familiar paradigm, and it's very powerful.