Hi Ryan & Dave,
Like the way we have option to get contacts present in the single list using getListMembers($List).
Is there any way of getting contacts present in multiple lists in single API call passing multiple lists at a time, instead of passing each list and getting contacts present in it.
That information would require a call to each individual contact ID and to compare the ContactLists->ContactList node. In our PHP wrapper it will return an array. So to answer your question, there is no way to do a single call to pull contacts who share multiple lists.
It is a great idea however and I will definitely list it as a possible feature enhancement.