Dashlet showing Opportunities of other groups

I have two Groups for diffferent sales teams and I have also defined their roles… they work fine if you are looking for the Accounts and Opportunities in the detailed or list view, but in the Dashlet it shows the opportunities and the outcome of both groups

When you click in the dashlet to drill down, you can only see the information of your group

Example:

It is very confusing for the users… is there a way to change this?