The assigned work filters in the Workload Balancer filter by work attributes and filter by user attributes independently of one another. For example, if you try to filter by Portfolio, the balancer will only show you those hours associated w/ that portfolio, not a user's full allocation across ALL of the projects/portfolios they've been assigned work on.
This becomes a major issue when you try to use the Workload Balancer to resource by each PM's projects. There is no way to show all projects that are owned by a particular PM and each of their project's assigned workers full capacity. Filtering by Owner ID will show all users unless you apply a user-related filter and in this case, there's no filter that exists to show all users associated w/ a project.
There needs to be a way to view the assigned work + working team by Project Owner.