I want to make a Nation Playable with two divisions (both with 10 teams) but I want to create the following system.
The 2nd Division:
1st Normal League stage
2nd Title Decider Playoff between the top 3 teams
3rd The winner will be rewarded with automatic promotion and the losers will play a Relegation Playoff with the 8th and the 9th of the superior league.
The First Division:
1st Normal League stage
2nd Last Place will be automatically relegated
3rd Title Decider Playoff between the top 2 teams
4th Will have a Relegation Playoff between the two teams who lost the Title Decider from the Division below and the 8th and 9th place.
I don't know how advanced rules work, so I would like a good explanation to help me make this Nation Playable.