Hello Bar can be set to show to a user who has previously visited or not visited a different Referrer Domains and Referrer prior to arriving at the current location your Hello Bar is set at by using the Targeting options.

First, you need to access the popup editor page and navigate under "Targeting" > Then click on Create New Custom targeting rule (not available on the free plan).

EXAMPLE: If you came on a target site/URL from another page https://neilpatel.com/blog/seo-companies/ 

The highlighted ones are the referrer and the referrer domain

Referrer in HB would be neilpatel.com/blog/seo-companies/ 

Referrer Domain would be neilpatel.com