Follow the below steps for changing a DNS for each site,
Open IIS, to click a
Bindings for Bold BI Enterprise site and click an
Add button for adding a new DNS.
You can add multiple binding to the Bold BI site in IIS.
Host name as your wish and click
Now open a Bold BI site settings page and update a
site URL for which site you want to change the DNS.
Now you will be able to access each site with the specific unique URL.
NOTE: You can change only the host name to site URL.
Save, now your site will be running with updated site URL.