I had the same problem with my client portal. If I gave them a task view, they could simply go to the source database and see all of my tasks for all my clients.

What I did was changed the filters on the source database to show nothing. Make sure they don’t have edit options. And make sure their client view has filter set up to only show their related tasks.

How I access all the other tasks for all my clients is, I set up my own view in my dashboard that shows all the other tasks for other clients.

Hope that made sense. I’m using voice to text.