Here is a summary of the steps:

1. Navigate to Custom Report Types in Salesforce
• Go to Setup → In the Quick Find, type Report Types.
• Locate and select Campaigns with Members and Ops.
2. Switch to Classic (If Needed)
• If the page does not load properly in Lightning (e.g., spinning icon issue), switch to Salesforce Classic.
• Once in Classic, navigate again to Report Types → Select Campaigns with Members and Ops.
3. Edit the Report Type Layout
• Click Edit Layout.
4. Add Fields Related via Lookup
• To add an Opportunity field, select Campaign Member Fields → Click Add Fields Related Via Lookup.
• Select the [AB] Associated Opportunity or [OB] Associated Opportunity lookup.
• Choose the desired field, e.g., ARR (Annual Recurring Revenue), and confirm the selection.
• Repeat the process if you want to add the field for both Account-Based and Opportunity-Based attributions.
5. Add Other Related Fields (Optional)
• You can also add fields related to Contacts and Leads from the lookup fields.
• If you need a field that combines Lead and Contact values, consider creating a Formula Field on the Campaign Member object.
6. Save and Apply Changes
• Once all necessary fields are added, click Save.
• The new fields will now be available for use in reports and filters.