Portfolios have the ability to split your clients up into different groups to help manage and sort them throughout your Kolleno system. Portfolios also have the feature of being able to split up your customers in groups and assign those different groups to specific users in the system.
In order to restrict the view please turn the "Restrict users to only see the portfolios they are part of" toggle on - for more information follow the link here
By toggling this on users will:
Only be able to see the customers from the portfolio they are assigned to
Only be able to see the invoices from the customers in the portfolio they are assigned
Only view tasks and reminders from the customers in the portfolio they are assigned
See the dashboard view information on the customers they are assigned to