You can configure filloutliers function to work as hampel function, but hampel function removes outlier using hampel identifier, you can have a look at its input argument it does not provide any other method for detecting outlier or replacing outlier. Whereas filloutliers function supports different methods for detection and replacement of outliers.
About using hampel function inside filloutliers function please refer to this link for learning about the input arguments accepted by filloutliers function: https://www.mathworks.com/help/matlab/ref/filloutliers.html
