I don’t think “Get Access” and “Manage Access” will satisfy your needs in this particular use case. You will be better served by making HTTP Requests to the search API and the submit access request API. Revoking entitlements via access request is currently limited to one entitlement per request, so you can’t do this in bulk. You will need a loop to submit an access request to revoke each entitlement.
Here is a workflow script to get you started. You can download this script and upload it to your tenant and configure as needed.
Revokeentitlementsbysource20230707.json (2.7 KB)
The main thing you will want to change is the loop input. You will want to specify a filter that will filter the sources you are interested in revoking entitlements for.
You will also need to update the HTTP Request actions to use your client ID and secret and your tenant URL. Otherwise, the script should work as-is.