Hey, this is not supported by default.
Take a look at the following open issue and the related disussion:
There is a plugin you could check out:
Other than that, I know that with RefinedWiki you can group spaces at least visually:
Hello Community, Jessica here from the Confluence product marketing team! Today I wanted to get your takes on project planning –– what works, what doesn’t, how do you know if you’re doing it r...
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