Search icon missing for Files tab on iPad

There seems to be no ability to search within the Files tab (iCloud songs, for example) when on the iPad whereas the ability does exist on Mac’s My Files equivalent tab. I notice that if I add a song to a playlist in the Music tab, it is then searchable within that the Music tab, but I would have to do that folder by folder, which isn’t feasible, plus it would be static (everything time I purchase new music and add to iCloud/Dropbox, I would have to add each song I purchase). Is there a way to turn on searching within the Files tab like there is on the other tabs? I also noticed the Dropbox/Box/Google Drive icons are in the Files tab, but greyed out and not accessible. What’s the best way to add a Dropbox folder to that tab? I’m using the paid version of djay Pro for iPad.