you are using the formula incorrectly here.

The offset function requires that the first item you insert is the
reference to the range of cells.
You have put the small() function here - but this returns only the nth
smalles value, and not the range.

Im not sure which direction you are wanting to offset the range, but I
will presume in a downwards direction, here is how you would want to
type the formula:

=offset( [ target range in here ],small(a1:a5,[ nth number here
])-1,1,1,1)

this translates to:

the value within the [ target range in here ] which is x number of rows
from the top, where x is the nth smallest figure within the range a1:a5