Supervisor in dreams can obviously link to issues about work and if there have been any situations (especially the day before the dream) that deal with working relationships and with working conditions then it may link to that. A supervisor may have a more general and abstract meaning showing that you need to grasp hold of a situation and take it very seriously. If you have a busy day ahead of you on the day of the dream it may be linked to that. If you are unemployed the dream may link to your thoughts about the job market or work in general.