Hi,
Welcome to the ehealthforum and I am glad to help you out.
Since you had the hernia repair 1 year back and now having this large lump just above the navel then it can be due to recurrent hernia also. 25% of all hernia recurrences present within a year of the hernia repair. Generally this can be done by surgical correction. Generally, this can be done electively, except in cases of acute incarceration or suspected strangulation.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care.