docs: document member list visibility organization security setting

contents/docs/settings/organizations.mdx

@@ -85,3 +85,22 @@ You can search the table by owner name, email, or scope. Click any of the **Owne
 The secret key value and key label are never exposed.
 
 > **Note:** This feature requires a plan that includes organization security settings. Only admins and owners can access this section.
+
+### Member list visibility
+
+Organization admins and owners can restrict which members are visible to non-admin members. This is useful for organizations that invite external collaborators into separate projects (e.g., B2B2C scenarios) and want to prevent those collaborators from browsing the full list of users.
+
+Find this setting under [**Settings** > **Organization** > **Security**](https://app.posthog.com/settings/organization-security). The toggle is labeled **Members can see the full member list**.
+
+When enabled (the default), all organization members can see every other member in the organization members list and project access control panels.
+
+When disabled:
+
+- **Admins and owners** continue to see all members everywhere.
+- **Non-admin members** only see themselves and members who have project-scoped access to a shared project (via explicit grants, role-based access, or the project's default access level).
+- The members table shows an "Other organization members" footer row so the shortened list doesn't look broken.
+- The access control panel hides the "has access as an organization admin" row when admins are not visible to the viewer.
+
+> **Note:** This restriction is only meaningful in **private projects** where the default access level is set to "No access" with explicit grants. In projects where the default access is "Member" or "Admin", all organization members have project-scoped access via the default and remain visible.
+
+> **Note:** This feature requires a plan that includes organization security settings. Only admins and owners can modify this setting.