Formatting from array to text aggregator by key with date range

Hello! I’m setting up an automation to collect data where each name (key) should be listed only once, followed by all associated dates in a single line separated by commas. Here’s the desired format:

Victoria: Saturday, Nov 16**,** Thursday, Nov 14 - Monday, Nov 18
Andrei: Thursday, Nov 14 - Monday, Nov 18

but now it is like that
Victoria: Saturday, Nov 16,Thursday, Nov 14 - Monday, Nov 18, Andrei: Thursday, Nov 14 - Monday, Nov 18

or
Victoria: Saturday, Nov 16,Thursday
Nov 14 - Monday, Nov 18
Andrei: Thursday, Nov 14 - Monday, Nov 18


The issue is that when I use a line break as a separator, each date appears on a new line under the key. But if I combine everything into one line, then the keys merge, and there’s no separation by each name.


and here with regex i take епу main information - only dates

If I remove the “new line” in the text, everything ends up on a single line, with no separation. Then, at the end, it’s unclear how to split it by key to get either everything in a single line or each entry starting on a new line. I can’t seem to achieve the desired format.

Could you please suggest the best way to set this up? Which module or method should I use to first gather all dates in a single line for each key and then properly separate them? Thank you for any guidance!