Advanced Insights is currently in preview so not all the functionality is there, however as a feature request it would be very useful to have the ability to search through the list of Managed Devices - Discovered Apps. For example, under Advanced Insights > Intune > Applications > Discovered apps on Windows & macOS devices, an option to search for an application and an option to select the platform
The Search function on the Intune tab should be working as expected now, thank you for filing this Idea :)