I've been using Poweramp since v2, and absolutely loved new v3 interface.
But the one thing I couldn't get used to (and I've tried to!) is that there is no "Filter..." text box now.
Here are some major points why regular Search is absolutely impractical for me (and pretty likely, for others too):
1) Exclusively alphabetical order of search results.
I have a lot of songs, over 6000 of them, from a very wide variety of artists and I regularly update my library. Say, I want to see the latest songs from a specific artist, who released over a 100 songs. And... now there's no way to do that, because all the search results are sorted alphabetically.
You might suggest that I could use search by artists and select a search result with artist playlist, but since artists often collaborate with each other, the names look like this: "Artist 1 & Artist 2", therefore there are multiple "artist playlists" featuring the same artist. All of which, by the way, usually contain a single song.
2) After playing a track from search, the current playlist becomes "All Songs".
One of the most common ways I used the filter was such: I picked from a specific folder a song I wished to start my commute with, put the phone in my pocket and let the next songs play on shuffle from that very folder.
Now, whenever I find that "starting" through search and start playing it, my current playlist is always made of all songs on my phone, not of the songs from my "commute folder".
3) The items in search results are oversized.
I deeply appreciated the possibility to change the size of rows/tiles in song lists, more specifically to make them smaller. But for some reason I can't do that in search results. For me that means it takes more time to scroll through the list to find a specific song.
Bringing back filter would be an obvious solution to all of the problems. A simple "filter" button could be added:
Another solution could be:
1) Adding so-called "List options" to the list of search results, making it possible to sort them by date added.
2) Allowing to limit the search to a specific folder, so when I tap on a song from search results, only that folder becomes current playlist.
3) Allowing to change size of search results, like everywhere else.
I really hope the developers consider this.