Grants (or denies) this role access to a hierarchy.
access may be "all", "custom" or "none".
If access is "custom", you may also specify the
attributes topLevel, bottomLevel, and
the member grants.
If access is "custom", the child levels of this
hierarchy will not inherit access rights from this hierarchy,
should there be no explicit rules defined for the said child level.
See mondrian.olap.Role#grant(mondrian.olap.Hierarchy, int, mondrian.olap.Level).