bspside

#!/bin/bash --

case $# in
    1) dir=$1 ;;
    0) printf >&2 'No arguments given.\n'; exit 2 ;;
    *) printf >&2 'Too many arguments.\n'; exit 2 ;;
esac

case $dir in
    west|east|south|north) ;;
    *) printf >&2 'Invalid argument: %s.\n' "${dir@Q}"; exit 2 ;;
esac

ensure_tiled ()
{
    bspc query -N focused.window > /dev/null \
        || return

    bspc node 'focused.!tiled.!pseudo_tiled.window' -t '~' \
        && bspc node 'focused.!tiled.!pseudo_tiled.window' -t tiled
}

bspc query -N -d focused.tiled > /dev/null \
    || exit

if bspc query -N '@/.focused' > /dev/null; then
    ensure_tiled
    exit
fi

case $dir in
    west|north)
        bspc node '@/1.!focused' -s '@/2.focused' || {
            bspc node '@/1.!focused#focused' -n '@/' \
                && bspc node '@/1.!focused' -s '@/2.focused'
        }
        ;;
    east|south)
        bspc node '@/2.!focused' -s '@/1.focused' \
            || bspc node '@/2.!focused#focused' -n '@/'
        ;;
esac

split_type=
case $dir in
    west|east) split_type=vertical ;;
    north|south) split_type=horizontal ;;
esac
bspc node '@/.!'"$split_type" -y "$split_type"

ensure_tiled

sxhkdrc

# Move the focused node to the given side of the tiled area.
super + {Left,Up,Right,Down}
        bspside {west,north,east,south}

The current version uses new bspwm features not released in 0.9.10 to simplify the code; if you want an equivalent version that is release compatible, see this revision.