Currently, there is 4 option to filter games, and as far as my experience of a year playing this game, they do nothing. I suggest introducing more option to filter and sort to find a game easier. Now, this is from my zero knowledge of game development so i don't really know the technical limitation of a game like CoN, but any of this implemented would help with the experience of searching for a game. What i came up with thus far:
Filtering:
- Filter by game speed (4x or 1x currently)
- Filter by game mode (Overkill, rising tide, WW3, flashpoint, ...)
- Filter by availability (Full or not, passed time limit to join or not)
- Filter by date started or ingame days/time passed

Sorting:
- Sort by ingame time passed
- Sort by number of players joined/ slots left

Any more suggestions in the comment are welcome

I...don't know actually. Maybe if you want to join a full game latter on for some reason, or maybe simply an option to hide the full and on-going games.
And I did a search, the only one I found with some details is this :
UX improvement - Add Game Mode to Search Filter for New Game
But he only mentioned filtering game modes, not the filters or sorting function.