Use rofi to select file or folder until file is selected, then print it.

rofi-selectfile.sh

#!/usr/bin/env bash
#
# rofi-selectfile
#
# Use rofi to select file or folder until file is selected, then print it.
#
# Arguments
#   $1=directory to start, defaults to "." (specified in variable default_dir)
#
# Adapted from: https://gist.github.com/thingsiplay/6c4bd13a106a4a609d69c402e675c137
#

# Filter modes: normal, regex, glob, fuzzy, prefix
rofi_filter_mode="regex"
# Prompt in rofi, defaults to scriptname.
prompt="${0##*/}"

# rofi command to run for each selection.
rofi="rofi -dmenu -p "$prompt" -lines 15 -matching $rofi_filter_mode -i"

if [[ "$1" = "--save" ]]; then
    SAVE_MODE=1
    shift
fi

dir="$(readlink -f "${1:-.}")"

while :; do
    selected=""
    file=""

    # List all folders in the directory and add ".." as top entry.
    filelist=$(ls --color=never -1Np --group-directories-first "$dir")
    selected=$(echo -e "..\n$filelist" | $rofi -mesg "$dir")

    if [[ "$selected" == "" ]]; then
        file=""
    elif [[ "$selected" == ".." ]]; then
        # ".." will be translated to go up one folder level and run rofi again.
        dir=${dir%/*}
    else
        file="$dir/$selected"
        dir="$file"
    fi

    if [[ -d "$file" ]]; then
        # Need to select a file, not a directory
        continue
    elif [[ -n "$selected" ]]; then
        if [[ "$SAVE_MODE" -eq 1 || -f "$file" ]]; then
            echo "$file"
        fi
    fi

    break
done