Keeps behavior that was enabled by default between 0.9 and 0.11. Imagine that you have simple structure:
tests
-- a
---- results
-- b
---- results
If checkbox is checked and you specifed tests/* as a parameters, plugin will upload it to tests/a/results...tests/b/results.
If this checkbox is disabled, plugin will upload it as a/results...b/results.
Pay attention - this option will be removed in next releases. So, it's better to avoid using it.