Obama was a little bit too young at the time to give a valid first hand accounting for where he was born.
Any information that he has on the issue is hearsay.
Both statements are true. Though it's possible such statements could be admissible nonetheless. For example, Rule 804 of the F.R.E. provides for when the declarant is unavailable to testify:
(b) The Exceptions. The following are not excluded by the rule against hearsay if the declarant is unavailable as a witness:
(4) Statement of Personal or Family History. A statement about:
* * *
(A) the declarant’s own birth, adoption, legitimacy, ancestry, marriage, divorce, relationship by blood, adoption, or marriage, or similar facts of personal or family history, even though the declarant had no way of acquiring personal knowledge about that fact[.]
Now, it's near impossible to conceive of a situation wherein this issue could arise which wouldn't be handled simply by offering a COLB (i.e., it would require a party needing to prove the circumstances of birth who could not otherwise procure a birth certificate).
But, theoretically, Obama's statements could be admissible.