How to display the required fields in the admin filters in Django?

Question

Django

Comrades, tell me, otherwise I'm looking for it myself and I can't find it. There are two simple models. Coin model - all crypto coins and exchange model are listed here, some crypto exchanges are listed here. Relationship 1 to many. (I indicate on which exchange certain coins are circulating)
When I go to the exchange model in the admin panel, then the coins for the filter (list_filter) are displayed on the right in the column,
everything is fine, convenient, but the nuance is that there are a lot of coins, and in only 10 of them are connected to the table with exchanges. So I want this filter to display only the coins used, and not all of them. How to do it?

Answer 1

well, so you make your filter from SimpleListFilter https://docs.djangoproject.com/en/4.0/ref/contrib/... in lookups you calculate "only used coins"