What would be the condition to show other than top 10 customers? Can you list few cases which you have thought of to get things started. Even I believe it is not just op 10 customer that matters all the time. You need to look for potential customers and Customers with whom business can be done in better than current in near future. They can lie anywhere in the data. So if user wants to take a look at that particular customer this makes sense.
Do you wish to see Top10 plus few customers or you want all the customer where top 10 should be made distinct to easy identification?
Let me clarify the requirement. I was asked to display Top 10 Customers and a few other Customers that the user wants.
For example, when the user opens the dashboard and sees the Top 10 customers, he realizes that he wants to see "Mike", "Tom", and "Jerry". When he finds out that the three of them are not in the Top 10 list, he can add the three of them to the dashboard. Notice that there is no way to determine in advance which customers the user wants to display. It purely depends on the user's interest when he opens up the dashboard.