How to know how many values has more than one ocurrence

Hi,

I need to calculate how many costumers bought more than one product sliced by company hierachy. I mean, a costumer may bought one product to a salesman in an office and another product to a different salesman in the same office. In that case the client will be considered multiclient for the office and the company but not for any salesman.

My input table (simplified) is something like this:.

 And the result I expected would be this:I tried with count, groupby, and other but he result is always the number of products that the client bought to each hiearchy level

Thanks in advance for your suggestions!