Ubuntu – How to list the files in other (non-current) directory

Use the unzip -j ("junk paths") option, which will extract just the files without recreating the subdirectories.

Find-based solution:

find . -maxdepth 1 -type f -printf '%f\n'

Bash-based solution:

for f in *; do [[ -d "$f" ]] || echo "$f"; done
##  or, if you want coloured output:
for f in *; do [[ -d "$f" ]] || ls -- "$f"; done

The bash-based solution will get you everything that isn't a directory; it will include things like named pipes (you probably want this). If you specifically want just files, either use the find command or one of these:

for f in *; do [[ -f "$f" ]] && echo "$f"; done
##  or, if you want coloured output:
for f in *; do [[ -f "$f" ]] && ls -- "$f"; done

If you're going to be using this regularly, you can of course put this into an alias somewhere in your ~/.bashrc:

alias lsfiles='for f in *; do [[ -f "$f" ]] && ls -- "$f"; done'

Since you noted in the comments that you're actually on OSX rather than Ubuntu, I would suggest that next time you direct questions to the Apple or more general Unix & Linux Stack Exchange sites.