I’m James from the Content API Team. Thank you for reaching out to us.
Could you please confirm if looking to retrieve or search a specific sub-account using websiteURL?
If yes, from the Content API’s perspective, there’s no option to search or retrieve a specific sub-account by specifying websiteURL. Instead, you can only retrieve the information of a specific sub-account by specifying the accountID upon your API call to accounts.get method or you can use the accounts.list method to view all the available sub-account within your MCA.
However, if I misunderstood your concern, kindly correct me and provide more details to your query.