Create a stem-and-leaf plot
Python 2, 78 75 79 bytes
s=-1
for i in sorted(input()):
if i/10^s:s=i/10;print'\n%d-'%s,
print`i`[-1],
Try it online!
Jelly, 17 bytes
Ṣµ:©⁵Ġṁ@%⁵®Q¤żK€Y
Try it online!
Retina, 38 30 bytes
Thanks to Neil for saving 2 bytes, and to Leo for saving another 6.
Byte count assumes ISO 8859-1 encoding.
O#`
.\b
$&
\B
0
D$`¶?.+
$*
Input is a linefeed-separated list of integers. Output omits empty prefixes.
Try it online!