Seeing the same for ks_meta: not being rendered/available when using $ks_meta
but each individual parameter defined via ks_meta are being available ($my_var1, $my_var2.
mgmt_parameters is being rendered (and seems to include the ks_meta):
so that $mgmt_parameters is expanded to a json struct containing what you might be looking for Plus some additional fields like tree and from_cobbler.
just add this in your ks_templete
# A_TEST = $ks_meta
# ANOTHER = $mgmt_parameters
# ANOTHER ONE = $from_cobbler and $tree and $my_var1
expanded as below (some value replaced with <skipped>):
# A_TEST = $ks_meta
# ANOTHER = {'my_var1': '2017.07.1', 'tree': '<skipped>', 'from_cobbler': 1, 'my_var2': 'a_value', 'partnumber': 'NONE'}
# ANOTHER ONE = $from_cobbler and <skipped> and 2017.07.1
So if you now the name of the variables passed via ks_meta this is easy job
else you need to parse the json from $mgmt_parameters to extract the values you need,