Recently I found out coc-explorer has float mode, which is really useful.

In case you don't know what is it, coc-explorer is a file explorer for neovim, but I think it could work with normal vim despite I didn't test.

First step, of course, install it , please go to the GitHub doc.

Then add a preset into coc-settings.json (you can open it by using :CocConfig command.)

"explorer.presets": {
    "preset-name-here": {
          "position": "floating",
          "floating-position": "center",
          "floating-width": 100,
          "content-width": -10,
          "floating-height": -5,
          "open-action-strategy": "sourceWindow"
    }
}
`

After that you can use it (in .vimrc):

nmap <c-e> :CocCommand explorer --preset preset-name-here<CR>

Note that you can change preset-name-here with anything you want. In my settings, I have 2 presets, one named float and one named static. It's easier to debug in the future.

Now you can press control + e to open the file explorer, it should float on top of everything.

Happy vimming :)