Find all the attributes you can use in search:

knife search node 'name:somenode' -F json | less Each key value pair can be used in search
For example,

"chef_environment": "_default"

Can be used like,

knife search node 'chef_environment:_default'

Find total number of nodes managed by Chef:

knife search node ':' | grep Node\ Name | wc | cut -d ' ' -f6

Find a node with a node name that begins with "jones":

knife search node 'name:jones*'

Find all nodes that use Ubuntu:

knife search node 'platform:ubuntu'

Find all nodes that use Ubuntu 16.04, Xenial:

knife search node 'codename:xenial'

Find all nodes that use Ubuntu 16.04, Xenial:

knife search node 'platform_version:16.04'