customizing Stakeholders's setting so that they can only see the shared dashboard in Azure Devops!

You may need to follow the access level with security group and area path permissions:

1. Use Stakeholder Access Level
   Stakeholders in Azure DevOps already have limited access by default:
   •    They can view dashboards and analytics views
   •    They cannot edit boards or backlogs
   •    But they can still see work item details, including “Assigned To,” unless further restricted
   
   
   2. Restrict Work Item Visibility via Area Path Permissions
   To hide backlog/board details:
   1.    Go to Project Settings > Project configuration > Areas.
   2.    Select the Area Path used by your team.
   3.    Click Security, then select the Stakeholders group (or create a custom group for limited users).
   4.    Set these permissions: 
   o    View work items in this node → Deny
   o    Edit work items in this node → Deny
   o    View work items in this node → Deny is the key to hiding backlog/board items.
   This prevents Stakeholders from seeing any work items under that area path, including “Assigned To.”
   
   3. Allow Dashboard and Analytics Access
   Stakeholders can still:
   •    View Dashboards (Project > Dashboards)
   •    Access Analytics views (if enabled in your org)
   To ensure this:
   •    Go to Project Settings > Dashboards and confirm the dashboard is shared with Project Readers or Stakeholders.
   •    For Analytics: 
   o    Enable Analytics extension if not already active.
   o    Use Power BI or Analytics views to create filtered reports (e.g., exclude “Assigned To”).

Stakeholder access quick reference - Azure DevOps | Microsoft Learn