Securing PII data reports along with non-PII reports in a workspace

Hello Team,

I do not have much idea on the security aspects w.r.t PowerBI.
Below are my basic clarifications:
1) When power bi report is published which refers some base tables/views, does the user require access to that table or is it just sufficient to have access on the workspace where this report is being published.

2)We have 10 reports in a workspace. Out of 10 reports, 3 reports are PII reports and 7 are non-PII reports.
Access has been given to a security group, say "PIIUsers" for base tables/views that refer PII reports.

Workspace can be accessed by 2 security groups
a)NonPIIUsers
b)PIIUsers

Can NonPIIUsers access the PIIReports as they both have access to same workspace.