Yes. You can view the current Nintendo Account through the user settings on your Nintendo Switch console.
Complete These Steps:
From the HOME Menu, select the user page for the user you wish to edit.
Select “User Settings”.
Scroll down to the Nintendo Account section, then select "Check Account Information".
If "Link Nintendo Account" is displayed here, then a Nintendo Account has not yet been linked to the user.
Select "View email address" or "View email address/Sign-In ID".
Enter the password associated with the Nintendo Account, then select "OK" to view the full Nintendo Account information.