How to change profile name/username to custom profile field

Hello, instead of having the user profile header title displaying the first and/or last name or username, I need to figure out how have them display a custom profile field instead.

The way my sight works, the profile forms contain a text field labeled “Listing Title” which represents their post/profile. For example, a listing title could be “House with 5-acres for rent”. So, instead of the profile header title displaying name/username I would like for it to display the custom text field.

Thank you in advance for assistance!