We have a loan secured by a 1-4 family investment property; the loan proceeds were used to replenish the borrower's cash used to buy the property and provide funds for future investment opportunities. So the funds were not used to directly purchase the property as the borrower previously paid for it with his own cash. Is this transaction HMDA reportable?

As you describe it, no.

ditto raitchjay.
The funds have to be used to purchase, pay a refinance or make home improvements to be HMDA reportable.
Replenishing cash, paying for college or a trip, etc., are not HMDA reportable.
Caveat: unless they're refinancing and taking out more to replenish, etc.

But what if the future investment is a home purchase? For example, borrower refinances current home with cash out, intent is to use cash to buy home in Florida - borrower wants funds available for when the find a home, no home has been identified. Would this then be reported as a purchase?

Yes.