How to select a particular dynamic item from the list - selenium

Question

This is my scenario:
create an id. (ID has a timestamp on it for the purpose of regression testing). For example abc_201502125566781. In other words, a unique id is created each time.
go to a different screen, select the same id in the pulldown menu, that was created in step 1. (Manual testing confirms that the id is available in the pulldown menu from step 1)
The following code works(not really), because it creates the new id in the search field, and grabs it, rather than the id from step 1 above. How can I tell the driver to grab the ID that was created in step 1. Thanks!
NOTE: domain_id has a timestamp assigned to it.
public static String domain_id = PropertyLoader.loadProperty("PVT_DOMAIN_ID") + now;
My code:
WebDriverWait wait = new WebDriverWait(driver, 60);
By xpath = By.xpath("//div[#id='overview_form']//select/option");
WebElement element = new WebDriverWait(driver,10).until(ExpectedConditions.presenceOfElementLocated(xpath));
element = wait.until(ExpectedConditions.presenceOfElementLocated(By.xpath("//option[.='" + domain_id + "']")));
String getThePreviouslyCreatedsiteId = element.getText().trim();
driver.findElement(By.xpath(PvtConstants.ADD_PAGE_SITES_PULLDOWN_SEARCH_FIELD)).sendKeys(getThePreviouslyCreatedsiteId);
driver.findElement(By.xpath(PvtConstants.ADD_PAGE_SITES_PULLDOWN_SEARCH_FIELD)).sendKeys(Keys.ENTER);
STEP 1:
/*1. From Left Navigation bar, select Setup > Sites*/
setup.setUp();
siteClickFromLeftHandMenu();
/*2. Click the +Add button*/
clickToAddNewSiteButton();
/*3. On Add/Edit Site screen, enter a valid Site ID (i.e. Site_timestamp) and click Add.*/
driver.findElement(By.xpath(PvtConstants.ADD_SITE_ID)).sendKeys(site_id);
verifyDisplay(site_id + "", By.xpath(PvtConstants.ADD_SITE_ID));
/*4. Enter the same value as domain.*/
driver.findElement(By.xpath(PvtConstants.ADD_SITE_DOMAIN)).sendKeys(domain_id);
verifyDisplay(domain_id + "", By.xpath(PvtConstants.ADD_SITE_DOMAIN));
driver.findElement(By.xpath(PvtConstants.ADD_SITE_DOMAIN)).getText();
//click to add the site
clickAddToAddSiteInTheAccount();
/*5. The message "Successfully Added" is displayed.*/
verifyDisplay("Successfully added.", By.id(PvtConstants.ADD_SITE_SUCCESSFULLY_ADDED_MESSSAGE));