This worked scenario will filter sales data based on the sales person accessing the dashboards.
Each user will need to have their data filtered based on a unique user identifier. The simplest way to achieve this would be to create a user based security filter so that all users can view the same dashboard but only see their own personal data.
The first step is to add the security filter to the dataset. In this scenario we matching the Opportunity Owner column with the User Security Identifier attribute.
Once saved we would need to activate security filters for the user and define the security identifier, in this case it would be John Hunt.
We can now repeat this process for each user we wish to be affected by the security filter.
Once complete every component and dashboard created from this dataset will now be filtered by the users security identifier, ensuring that each user only has access to their allocated information. Which means only a single master dashboard would need to be created and shared with all of the users, with no risk of a user being able to see restricted data.