// 1
const isOutOfRange = var < limit;
const isMultipleOf3 = var % 3 === 0;
const isSomething = someCostlyCalculation(var);

if(isOutOfRange && isMultipleOf3  && isSomething ) {
 // ..
}

// 2
if(var < limit && var % 3 === 0 && someCostlyCalculation(var)) {

}