Hybrid

There are five Specializations - Strategists, Commander, Armoured, Assassin, and Spec Ops. One of these needs to be maxed out to their 5th tier with a total of 40,000 XP.

The XP you earn normally from playing matches counts towards one of the Specializations so long as you have selected the Specialization you want to work on. You do this by selecting a continent, then the correct part of the map with the corresponding icon that appears just to the right of the piece of map you have selected. Once selected, play your match, earn as many kills, assists, drone/warbringer/preyon kills/assists as possible, and you whatever amount of XP you earn for the match will go towards the Specialization.

The Specialization must be maxed out during the same season. If the season ends, your progress will be reset.

However, with the community for this game pretty much being non-existent, I've yet to see a season come to an end. This also means that the only way to make progress with earning XP is to participate in boosting sessions that require six boosters in order for the session to go ahead and run smoothly.