Here's what I need. I run a business, I use my personal Android phone (Samsung Galaxy S8) for 100% of my calls. It's not a problem. But I have a lot of clients whose numbers I don't have memorized. I could put a hundred contacts in my personal phone so I would know who's calling, but, I don't want to fill up my phone's contact list with people I only talk to occasionally.
When I look at my contact list, I want to see my friends and family only. Is there an app that will handle sort of a 'secondary phonebook' with business contacts only, that will still work with caller ID?
And if you are going to comment 'you need a second phone for business stuff', don't bother. That's not what I want to do, and that's not what I'm asking. This is a question about whether there is a particular Android app that will solve my problem (or an Android setting), not anything else.