To see all your database contacts, follow these steps:
From the modules menu
icon, click the Single Customer View (SCV) 
icon.Open the New Contact Segmentation.
From the Data Tree section, drag and drop the Demographics node into the Contact Selection section.
Once it's connected, the customer's number will be displayed by the Contacts Count
icon.Click Results, then browse the customers lists displayed to you.
📌Note: The customers information preview will show you the following details:
The customer's title if available.
The customer's first name.
The customer's last name.
The customer's email address.
The customer's mobile number.
🤓Tip: If you want to view a specific customer details, you can review this article.