With Subdomains, you can see a breakdown of traffic share per main domain and their related subdomains.
You can categorize the traffic share to see what's relevant to your needs. For example, viewing the main domain target.com and then the subdomains login.target.com and rcam.target.com, you can differentiate general traffic and customer traffic, as access to the two subdomains would indicate it's their customer base.
Within Company Research > Subdomains, you can see traffic share for subdomains for up to five sites.
In the table, you can see:
Hover your mouse over the domain name to see an overview, including Global Rank, Country Rank, and Last Month Visits.
Click the domain to see the Website performance.
Click the arrow to view the website in a separate tab.