Custom URL for "lists" subpages

Hi all, have a bit of a technical question.

Context: I have a datatype called “lists”. I also have a page called “lists” with the URL “xxx/lists”. The lists page has “lists” as type of content and I can thereby alter the custom URL to e.g. “xxx/lists/list1” which works. I want the lists page to be an overview of all lists. Thus if you are directed to the lists page it shouldn’t contain the data of any particular list and it should only include the URL “xxx/lists” thus not any sub-URL such as “xxx/lists/list1”.

The question: How can I create an overall page called lists (which should not be datatype = “lists” as it should contain a repeating group of all lists) AND subpages under the “lists” subdomain that are dataype = “lists”?

Thanks in advance!