Select only the first N instances of a value in a table

I feel like there are a hundred simple solutions to my problem but I can not come up with any!! I have a table full of patients and their Primary Care Providers. Some providers have 100 patients, some only have 30. I want to be able to select only the first 30 patients for each provider and make a new table.

One solution I thought of was to create a column that numbers the patients from 1 to N and then starts over when it gets to a new provider. For example, if I could go from image one (no index column) to image 2 (index column that starts over when it gets to a new provider), I would be home free. However, I can't figure out how to make an index column that resets to one when it gets to a new provider.

I would greatly appreciate any help on this. Like I said, there are probably many ways to get this done, but I've been thinking about it for weeks and searching forums, talking to AI, and I can't get a solution!

UPDATE: Replaced screenshots with .xlsx.