Here is guide to some of the M/M content than can be found.
Guilmon (Dom) X Gomamon (Sub)
1.One currently bugged encounter in Gaia Jungle (v_0.3).
2.At Gomamons home the end game state, if the Duo has gotten close over the game. The Chomp leads to a lewd licking.
Controlling Gomamon has few M/M scenes at the Inn Washing room. Just throw the fish friend to a washer and explore the room for "assistance".
Guilmon X Gaomon (Sauna)
At the dojo, agree to spot with Gaomon. Then beat him at the "Boulder Race" minigame. Talk to him inside the rock pushing game room after the race and agree to join him to the dojo Spa.
Guilmon X Gumdramon
At the Dojo, around the end game. Sneak behind him at the floor crushed marked corner. (Another scene at the inns Dining hall, sneak behind him and proceed from there.
Guilmon (Sub) X Hackmon (Dom)
At front of the ogre camp, Hackmon challenges you to a 1 on 1 fight. Agree to the duel and then simply lose it at the movement part (fireballs vs claws). Once you are down, start acting submissivly. See what follows.
Also has a continuation scene after the Ogremon issue is solved. Inside the Bancho Headquarters, Hackmon demands you to join him in an... "Urgent" mission.
(Hackmon is quite prideful and dominant. Only found this submissive lewd route with him so far.)
The Leomon forgiveness is possible, certainly was the hardest thing to find so far. Might need a new game to get it right.
Generally choose things that are beneficial for the Banjo Brigade. Recruit more members, save friends.
But the most important part is easily missed. You need to avoid triggering the 1st sight encounter with Lilithmon inside the Twilight Ruins until you have gotten the Leomon Memories.
Once you have resolved the Leomon Memory maze. Trigger the encounter and Try to talk it trough. Suggest exchanging something for PawnChessmon safety. If you have the Leomon Memory, its a new trade option.
But at the end, refuse to give it.
After that situation is resolved, try returning Leomon memories, but this time... With Deep Trust.