"She's playing 3D chess" is a cliche way to say that someone is operating on a far superior level to anyone else in the situation, making moves that other people couldn't even perceive, let alone pull off.
But I don't love that metaphor. It implies you are just playing the same game at a greater level of complexity, whereas for me, the real gain is not in dialing up the complexity but in changing your relationship to that particular game, seeing it as just a single move in a bigger game instead (which, in turn, is just a move in a yet larger game!).
That is: don't play 3D chess, play fractal chess instead.
The best board game analog to this that I know of (if you know a better one, let me know!) is Twilight Imperium. In TI, players engage their forces in Risk-style battles for control over individual planets. In turn, control over planets provides additional resources as well as opening up galactic laneways for future deployment. Plus it might give you a shot at controlling the capital planet of Mecatol Rex, which then boosts your power and influence. But accruing resources, maneuvering around the galaxy, and controling Mecatol Rex are all just means to achieving the ultimate goal: reaching 10 victory points before anyone else.
Putting it another way: each battle for a planet is like a game in itself, but your concern isn't with winning that game per se but rather with applying the results of that victory to the game of controlling more planets. And controlling different planets is like its own game, but again you don't really care about that game for itself but rather for what it brings you in the next game up of winning victory points (or potentially another intermediate game layer before you reach the ultimate victory point game).
Incidentally, the players who are most aware of the fractal nature of the game are the ones who tend to win. Many players get attached to 'winning' the lower-level games at the expense of winning the full game, for example hunting down a player who attacked them in the past even though it doesn't serve their strategy to do so.
Applying this to real life
The way to apply this to real life is to remember that most times you are trying to win some contest, that contest is not important to you on its own. Rather, it takes its importance from what it gets you in the more important games higher up the chain – and you should focus on those games rather than getting sucked into the current one.
- Do you really want to 'win' this argument with your spouse, even though it will be a counter-productive move in the more important game of "have a good marriage"?
- Getting your way on this specific decision about a project at work probably isn't the game you want to win; you're only doing this because you want to help your career and get promoted, right? So take a step back and ask yourself whether this decision is really going to make a difference either way for your career.
- In fact, "having a good career" is really just a strategy in the bigger game of "life a fulfilling life" – are the actions you're taking to optimize for the career strategy also a net positive for the happy-life game, or are you maybe on a locally optimal but globally stupid path? (this point brought to you by Paul Millard's Pathless Path idea)
- Taking cold showers, waking up early, intermittent fasting, etc. are all mini-games in service of higher games (health, productivity, and so on). And these higher games are, once again, in service of the "have a fulfilling life" game. So: are the sacrifices you're making by 'winning' these mini-games actually contributing positively to the overall game, or are you perhaps missing the forest for the trees?