There is no method provided for this purpose. You would need to extract the x and y limits and figure out which points fit within the range.
With the XData not needing to be contiguous, extracting the data correspond to the current x limits would in general require creating a cell array which could end getting populated with as many as length(x) different components. For example,
x = 1 + rand(1,100);
x(2:2:end) = 0;
then with an xlimit that was greater than 0 but less than 2, you could end having to break into segments {x(1), x(3), x(5), ...}
