The xpath is invalid, or is a single |
wait5.until(ExpectedConditions.elementToBeClickable(By.xpath("//a[@data-period='R6M'] | //span[@title='FYTD']"))).click();
You can also use ExpectedConditions.or fo this
wait5.until(ExpectedConditions.or(
    ExpectedConditions.elementToBeClickable(By.xpath("//a[@data-period='R6M']")),
    ExpectedConditions.elementToBeClickable(By.xpath("//span[@title='FYTD']"))));
To get WebElement from one of two conditions you can build your own implementation
public ExpectedCondition<WebElement> customCondition(By... locators) {
    @Override
    public WebElement apply(WebDriver d) {
        for (By locator in locators) {
            return ExpectedConditions.elementToBeClickable(locator).apply(d);
        }
    }
}
WebElement element = wait4.until(customCondition(By.xpath("//a[@data-period='R6M']"), By.xpath("//span[@title='FYTD']")));