Open SharePoint 2013 Central Administration site, and then click Manage Service Applications section, click Configure Syncronization Connections under User Profile Service .

Please note that only one user profile has been imported to SharePoint 2013.

For importing new profiles to SharePoint you have to create a new connection to, in the most times, Active Directory.

So, please click on “Create New Connection”

But you will receive an error that says “Cannot navigate to the requested page because the service is not running”.

This means, that you have to start the service under “Services on Server”.

You have to fill the password. BUT be aware the user needs “Replicating domain changes”. This is a requirement because without this, you can’t import changes from SP to AD, or AD to SP.

If you don’t know how to do it, please connect to your Domain Controller and click on “Active Directory for Users and Computers”.
Made a right-click on the domain and click to “Delegate Control”

And give your user who has to replicate domain changes the adequate right.

Then under “Services under Server” please start the User Profile Synchronization Service but be aware, it will take more than 5 minutes before start. So, if it does not start directly do not panic.

Now, you can make a new connection to your Active Directory.
Please provide:

• A connection Name: SPPIRATE AD 
• Type: Active Directory
• Forest name: SPPIRATE.NET
• Account Name: DOMAIN\USER
• Password: PASSWORD

Under populate containers; please choose what exactly you need. In the earlier version of SharePoint (2007) you couldn’t choose your containers and it was a real disillusion, because it took everything Even Service Accounts.
But there is a workaround for this: http://www.gknzcfc.net/subsite/user-profile-syncronization-importing-different-ou-in-sharepoint-2007.html

And you can now Start a Profile Synchronization.

And you can see that our imported User Profiles has been updated from 1 to 4. Meaning that the users has with their profile has been imported to SharePoint 2013.

You can now made a search on a specific user and you will be prompted with that user.