My main table is all of our client records. I 'd like to hit a button that will open their billing entry that's on a related table. Any formula ideas?
Before I give the slightly complicated answer for a formula, why not just put a report link field on your Client Record to show a report link to the billing records or an actual embedded table of the Billing entries right on the client record? The report link field will have been created for you on the left side of the Relationship between Clients and Billings