Display resolution options are poor!

I have my Mac mini 2014 work as a file server and ssh server. For some configuration I regularly do share screen and check if everything ok. But using it a while, I found there's only 2 options for display resolution. One is 1280 x 1024 and the other is 1024 x 768.

Ideally, I'd like to make the full use of my MacBook, which has great screen. Thus I want to add a custom resolution(2300 x 1440) for my Mac mini.

Is there any way to do that?

*I tried to press ⌥ key so that I can see what's more, there has been nothing.