2 answers
Hi,Greetings!You should be able to retrieve the sharing rules if you specify the Object to retrieve the related rules as below:
Please try the above package.xml and retrieve to see,if still see the same error.Kindly mark it as best answer if it helps so that it can help others in the future.Warm Regards,Shirisha Pathuri<?xml version="1.0" encoding="UTF-8"?>
<Package xmlns="http://soap.sforce.com/2006/04/metadata">
<types>
<members>ObjA__c.*</members>
<name>SharingCriteriaRule</name>
</types>
<types>
<members>ObjA__c.*</members>
<name>SharingOwnerRule</name>
</types>
<version>51.0</version>
</Package>