Can contact only be on one Mailchimp List?

Can contact only be on one Mailchimp List?

Hi, I am installing the mailchimp app (extension?) to sync mailchimp to zoho crm.  The functionality that I want is to be able to manage mailchimp lists in zoho, then sync to mailchimp.  So, if I get a new Newsletter contact, I want to add them into Zoho, then add them to a mailchimp list (in zoho), then sync it to mailchimp.

The problem I am having is if I want someone to be on two lists.  I have one list for newsletter, and another for webinars invites.  If I add someone that is CURRENTLY on the Newsletter list to the Webinar list, then run "selective sync" on these two lists, they only show up on the Newletter list and not the Webinar list in ZOHO (that is, if I go to mailchimp lists in ZOHO, they are on one but not the other). They DO show up correctly in MAILCHIMP.  But, to the extent I want to manage my mailchimp lists in one place (Zoho) this is very confusing.  

Please advise if I am doing something wrong?