Signals Notebook: Attribute values remain visible in search filters even after removing group associations

Cause

- The user's role has Manage Attributes permissions (e.g., System Admin or Config Admin).
- There is a security policy rule granting read permissions over other experiments these make all attribute values appear in filters if the user has read access to content containing those values (e.g. World Read, Full Control).
- Experiments with other attribute values were manually shared with the user.

Solution 

To hide the values outside the user group associations:

- Review the user role permissions.
- Review the security policy rules for the user group.
- Un-share manually shared experiments with the other attribute values.