Yes, I think that (1) can have both of those meanings. But I don't think the two meanings are necessarily separate meanings. Meaning (b) simply expresses a possible reason for (a), to capture (1)'s rhetorical flourish.
We could phrase meaning (b) likes this: I am happy to be anywhere, because I could have been nowhere, and I think being anywhere is better than being nowhere. Meaning (a) by itself could be expressed like this:
(2) I am happy wherever I am / go / find myself.