Sophos XG Firewall - User Searching In Policy

Dear Concern,

I have configured Sophos XG Firewall as a Proxy and I have several users in a single Policy. For Example, we have 400 users in a single policy and I want to search user in the policy so I can delete it from the policy instead of searching manually. Kindly suggest to me the way I can find users in the policy easily.

Thanks in advance