Get the definition of a hierarchy view with a normal user?

Hierarchy view definition (actually all column views) are null in "SYS"."VIEWS". (e.g. {"NODESTYLE":"levelName","NODETYPE":"string","ROOTNODE":"(all)","RUNTIMEOBJECTTYPE":"blob","SOURCEQUERYSCHEMA":"SYSTEM","SOURCES":[{"attributeMapping":{"TIMESTAMP":"TIMESTAMP"},"levels":["TIMESTAMP"],"name":"....","orderBy":["TIMESTAMP",true],"schema":"_SYS_BIC","type":"leveled"}],"SOURCETYPE":"leveled"}

They are only available in definition of "SYS"."CS_HIERARCHY_DEFINITIONS_", but the problem is only SYSTEM user can read this table.

But how could I read definition of a hierarchy view using a normal user?

Since SYSTEM has no grantable option to tables in SYS schema, so it's impossible to grant select authorization on tables in SYS to other normal user.

Is there any other view or procedure to access this?

Thanks a lot in advance!