Figure out how to properly present single-domain, multi-list view inside list view and in phonebook

It would be beneficial to discuss and work on how to better present cases where you have a single (sub)domain but > 10 (or maybe >100) lists tied to that. In list view, that would get compacted and only the 5 busiest lists are shown by default, with the rest inside a dropdown. There may also be better way of building a phonebook (the front page) for this sort of setups.

Start by reviewing the list view and phonebook (front page) entry points to understand how domains and lists are currently presented. Compare the single-domain case with setups containing more than 10 lists, then define and document the desired compact list and phonebook behavior before implementation.

Written by the indexing model from the issue text.