What is OLS in Power BI?

OLS in Power BI means object-level security, which is about restricting access to specific tables and columns visible to users in reports, which is helpful in hiding sensitive data from viewers and preventing them from being able to access it at all.
While RLS filters data by rows, OLS filters access by hiding entire objects.

Even thought Power BI Desktop does not natively support OLS, it can be implemented by using external tools like the Tabular Editor.

To add OLS roles to the desktop, follow these steps:

1. Create a role in the Power BI
2. Navigate to the Tabular editor with the same model
3. Open a role
4. And set object permission to “None”, to remove from access
5. Save and come out

You can test it on the desktop by clicking “View as” on the modeling tab.

In the Power BI service, you can use the Security option for datasets to assign roles to users.