If you used to go to Advanced Settings and see our trusty Advanced Find on the command bar, and suddenly it has disappeared after a Microsoft update, do not worry!
Microsoft has again moved the old Advanced Find or I would even say hidden it, to drive us towards the Dataverse search.
I encountered this in Dynamics 365 Customer Service and Field Service, so I'm not entirely sure it would affect Sales, Marketing and the rest. Highly likely all of them.
Where to find the old / classic Advanced Find
Click on the settings wheel and go to Advanced Settings
Click on the Dataverse search bar
and then click on 'Search for rows in a table using advanced filters'.
This will bring up a side panel, with the 'Switch to Classic' button
Clicking this will bring you to the old / classic Advanced Find.
What's different now is that it opens up as another tab in the browser, unlike previously where it would be a pop-up. So you will be able to bookmark and save this for next time!
Navigate to Advanced Find directly through URL
If you'd like, you can also utilise the below URL, just replace with your context values:
https://<your-dynamics-url>/main.aspx?appid=<app-id-you-get-when-you-click-advanced-settings>&pagetype=AdvancedFind
Hope this helps!