fzf
A command-line fuzzy finder
... in fullscreen mode, but you can make it start below the cursor with the height option. Unless otherwise specified, fzf starts in "extended-search mode" where you can type in multiple search terms delimited by spaces. Fuzzy completion for files and directories can be triggered if the word before the cursor ends with the trigger sequence, which is by default **. Fuzzy completion for PIDs is provided for the kill command. In this case, there is no trigger sequence.