Historically, we always had separate VSO projects for each logical project being developed. This is especially important, since for each project it is necessary to have separate lags. Each project has its own product owner.

We have a team of 10 developers who work between these projects over a 2-week sprint.
This setup caused serious problems when using VSO Scrum tools:
- Multiple combustion scheme, cumulative flow and speed diagrams.
- Combines team member ability during sprints
This makes it very difficult to monitor progress during sprints and to plan effectively for the next. This led me to create https://stackoverflow.com/a/166778/
Based on MrHinsh's answer, I now have 1 VSO project, and then breakdown of all projects into areas:

This means that we have the following commands in Project (all are "displayed" in the corresponding areas):
- Project team 1
- Project team 2
- Project team 3
- Project team 4
Would it be nice to add an extra layer to the area structure?
For example, projects belong to a certain product. Logical grouping can be useful for reporting (speed / burning date / etc.). This is consistent with our organizational model:

In my opinion, we would need to create two more teams:
- Product A Team
- Product B Team
Additional questions:
This, in essence, means that the backlog from the product group will accumulate in the backlogs of Project 1 and 2. BUT, members can still add items to the backlog of Product A, which is somewhat wrong because backlog items should only be created in Project 1 and 2 There is no way to disable this?
I played with this in VSO and found that no matter what area a member belongs to, he / she always has access to all areas of the project. This means that access control is not entirely possible. In addition, this means that I cannot “hide” the level of the product.
In addition, when navigating to the command area, there is no clear indication of the hierarchical structure (see screenshot below). This may be misleading to members. This would be another reason to hide such product levels. I did not find a way to do this.
