Simple but highly effective

Would be a 5 star rating but the documentation on nested tags appears wrong. To get a nested accordion working it needed this:

[su_accordion]
[su_spoiler title="Plain spoiler" style="fancy"]Spoiler level 1[/su_spoiler]
[su_spoiler title="Click me to see nested accordion" style="fancy"]
  [_su_accordion]
    [su_spoiler title="Nested Spoiler title 1"] Spoiler content level 2[_/su_spoiler]
    [su_spoiler title="Nested Spoiler title 2"] Spoiler content level 2[_/su_spoiler]
    [su_spoiler title="Nested Spoiler title 3"] Spoiler content level 2[_/su_spoiler]
  [_/su_accordion]
[/su_spoiler]
[su_spoiler title="Plain spoiler" style="fancy"]Spoiler level 1[/su_spoiler]
[/su_accordion]

Note the prefix underscore on the closing tab only in the nested spoilers.