Today I went into my Contacts and selected the list that I wanted to View. I easily could have wanted to select two Lists and then View & Manage those particular Contacts. However, after selecting one List, the option to View those Contacts in that List was no longer available on my Windows PC's screen; by clicking the check box, the 3 dots where I could View Contacts disappeared.
Not a regular user, so common sense navigating CC is especially important to me.
So, my suggestion is to have the Actions button at the top of the list of Lists with check boxes include the option to View Contacts. For example, I might want to tag all the Contacts that fall within 3 or 4 Lists so that I might Tag them and then choose All Contacts for a campaign and THEN filter out those Contacts with the new Tag. It doesn't make sense to have to Tag individual lists one at a time, nor does it make sense to select several Lists and NOT be able to view those Contacts.