Hmm, try this:
1. In your 'Campaigns', try creating a formula field that outputs the text '[CLIENT NAME] - [MONTH YEAR]', so e.g.
'Efficient Growth Consulting - November 2023'
2. Click the field header of this new formula field so that the entire column is selected then hit CMD / CTRL + C
3. Click the field header of the linked field to your "Monthly Campaigns" and then hit CMD / CTRL + V
This should create one record per record month combination in your 'Monthly Campaigns' table
After that, you can create rollup fields in the 'Monthly Campaigns' table to sum up the calls and prospects, and create a formula field to display the prospects / calls value
And the new table would be used in your Interface, filtered to show the records of the selected client
To automate it, you'd just need an automation that triggers whenever a record in 'Campaign' is linked to a customer, has a month year value and has an empty linked field to 'Monthly Campaigns', and its action would be to paste the value from the field you created in step 1 into the linked field to 'Monthly Campaigns'
Should do what you need I think!
