By default, the Contacts app on the Samsung device displays contacts from all accounts, and the displayed contact list can be filtered so that we can display single or multiple accounts. In addition to accounts like Google and Samsung, you can also view contacts stored on the SIM card or phone memory.

Android 10 (One UI 2.0)
Step 1:  Open the  Contacts -App
Step 2:  Open the  menu
Step 3:  Tap on  All contacts
Step 4:  Choose desired  Source / Account
  1. Open the Contacts-App
  2. Open the menu
  3. Tap on All contacts
  4. Choose desired Source/Account

Samsung Instructions