I believe what you want to do is click on the line numbers, which should take you to that exact point in the file.

Could it really be that simple?!

Holy shit. It really is that simple.

Thank you.

you can also use alt+enter while the cursor is inside of a multi-buffer, and it will open at that point in the file.

Even after figuring this out for myself I still struggle to do it fluently.

There's a setting that will allow you to double-click to open a file from the multibuffer which I find more natural:

  { "double_click_in_multibuffer": "open" }

Took me a bit to find this, but you can click on a line number in multi-buffer to open that file at that location. I think their default assumption is for you to not use the mouse much. If you're using vim mode g+[space] will open the file where your cursor is. I think it's alt+return in normal mode but either way there's a shortcut hint on the right side of the header for the file your cursor is currently in.

It also tell you that "alt-enter to jump to the file" in the "header".