If this were Swedish, you would should written (to make it more clear):

Here you can ask about the members on this site; ask for someone to help you with a project; or ask where to find such people.

I've never seen this use if ; in English, and it's unfortunately rare in Swedish to.

But in this case, you're just wrong.

It should be:
Here you can (ask about the members on this site) or (ask for someone to help you with a project or where to find such people).

I can admit that my writing might be uncorrect, but I really don't know how to make it more correct. Maybe a comma before the first "or" would make it more clear? But not accourding to any rule...