How do I block private numbers on a Android 6 Marshmallow (or 6.0.1) smartphone?

I keep getting calls from private numbers at night and I would like my phone to auto-reject them.

I have a Lenovo P2 smartphone running Android 6.0.1 and it does not have that option anywhere in the menu. My old 2011 Samsung had it, but this 2016 Lenovo seems to have taken it off.

How do I block those annoying private-number callers?

Yes they did make that more difficult. With my old Samsung S3 w/Android 4.3, I could simple hold a finger on a number in the log until a menu popped up and could block it from there.

For my J7 w/Android 6.0.1 if you open the phone app and goto MORE > Settings > Call blocking > Block list and then press LOG button to select a call from the log. What ever happened to making things easier instead of more difficult?

I do not have that option in Android 6.0.1.

In my phone app, when i tap the MORE icon i have a "Call/Messages blocking" icon. When i tap that icon i have 4 options:
- Block mode (which has 3 options: "only block blacklist numbers", "only block whitelist numbers", "only accept from whitelist")
- List management (has a whitelist and a blacklist, on either of those you can "Add fom contacts" or "Add manually" - for this last one you HAVE to provide a phone number. No option to add from log or to add private numbers.)
- Blocked history
- Import/export black-and-white list

I did not find a LOG button anywhere.