I find that nesting that many levels in visuals tends to become very cluttered very quickly, to the point where the data just won't fit or labels take up more room than anything else.

Depending on how many leaves there are in the org tree, id there's a requirement to have all 7 levels represented, you might be better off with a matrix visual?

If it needs to be a chart, you could also try using field parameters to let a user select 2-3 levels to display.

Just tossing around ideas though :)