Very easily, use CTRL+W, SHIFT+T.

See the help page:

:help CTRL-W_T

Note that this is case sensitive: <C-W>T is different to <C-W>t.

The long-and-straight-forward way would be to open a new tab and open the file's buffer there.

:tabnew
:b FILE_NAME

:b can TAB-complete from arbitrary parts of the file name, so this shouldn't take too long.

Canonical Solution

Suppose there are two buffers:

:ls
  1 #h   "match_this_partially.md"  line 1
  2 %a   "food/tacos.txt"           line 1

You currently have food/tacos.txt open. You want to open match_this_partially.md in a new tab.

Simply use the following:

:tab sb partial

-- or --

:tab sb 1

You can also use wildmenu tab completion in place of partial.

long form:

• :tab sbuffer {buffer}

help:

• :help :tag
• :help :sbuffer

Alternative Keyboard Solution

Open file in a new split open it in a new tab with the following:

<c-w>T

Use case

Note: for me ]b simply is mapped with nnoremap <silent> ]b :silent execute v:count.'bnext'<cr>

If I have few buffers I might do something like this:

1. <c-w>v -- create a new vertical split
2. ]b -- navigate to next buffer (essentially with :bnext)
3. <c-w>T -- open split in new tab (this destroys the split in the first tab)