Use Single Picklists in Restriction and Scoping Rule Criteria

Now when you create a restriction or scoping rule, you can select a single picklist to choose which users this restriction rule applies to. Selecting a picklist offers more flexibility because you can choose custom picklist values as you build rules. Single picklists are supported in rule criteria in Salesforce or via an API, but multi-select picklists aren’t.

Where: Restriction rules are available in Lightning Experience in Enterprise, Performance, Unlimited, and Developer editions. Scoping rules are available to customers using Unlimited Edition with Signature or Premier Priority Support.

How: To use a picklist in your rule’s user criteria, navigate to Object Manager in Setup. Select the object that you want to add a rule to. Click Restriction Rules or Scoping Rules. Name and describe the rule, and activate it. Select a picklist as the type field in user criteria, and choose a picklist value to determine which users the rule applies to.

https://help.salesforce.com/s/articleView?id=release-notes.rn_forcecom_sharing_single_picklists_in_user_criteria.htm&release=236&type=5