Sounds like https://world.optimizely.com/blogs/Duong-Nguyen/Dates/2014/1/Country-Region-drop-down-lists-in-All-properties-mode/ is what you want but also check out
https://gregwiechec.com/2018/03/hide-tabs-and-properties-in-edit-mode/ and https://developerschallenges.com/2017/11/02/episerver-all-properties-component-for-showing-and-hiding-content-using-a-drop-down/
As you could tackle it a few different ways but I believe the first is the solution
Great articles, thank you. I'm going to try it
So I have 2 custom dropdowns in a CMS page and have them loading via separate selection factories. However, I want to load the second drop down list based on the selection of the first rather than load all data once. Is this possible?
Can I somehow tag the first drop down with an onlcick to trigger and ajax request?