According KB a custom path can defined with

export COLUMNSTORE_INSTALL_DIR
export LD_LIBRARY_PATH

https://mariadb.com/kb/en/library/installing-and-configuring-mariadb-columnstore/#running-postconfigure-as-non-root-user

but this leads ti following errors.

/home/mysql/test/mariadb/columnstore/mysql/mysql-Columnstore: line 89: /home/mysql/mariadb/columnstore/bin/getConfig: No such file or directory

/home/mysql/test/mariadb/columnstore/mysql/mysql-Columnstore: line 245: my_print_defaults: command not found

/home/mysql/test/mariadb/columnstore/mysql/mysql-Columnstore: line 357: cd: /home/mysql/mariadb/columnstore/mysql: No such file or directory

For some cases the expoeted variables will not be respected in every case.

Workaround:
include the export commands in
.bash_profile/.bashrc

Export command set all variables for current shell and all processes from current shell.

So some processes / shell will not be initiated from the current shell and
the env variables fall back to default values.