The only requirement to get back to the Regular queue is to keep playing fairly: you don't have to win battles or be the first on your team, just don't leave.
The number of battles you have to play this way depends solely on the number of battles you withdrew from (it's not 1:1 ratio) and the number of time you were reported by other players before. The more fair matches you play, the sooner you'll return to the general queue and will be matched according to your league.
NOTE: You don't have to play solo, nor you need to play Domination only. Squad battles or matches in Skirmish would be just as good in terms of getting out of the Low Priority Queue.