Requesting help with query

try this using @cascade:

{
  q(func: type(Position), orderdesc: employedFrom) {
    uid
    name
    employedBy{
      name
      location
    }
    employedFrom
    employedUntil
    responsibilities_include @cascade {
      name
      skills @filter(eq(name, "DOCKER")){
	    name
      }
    }
  }
}

@cascade says "get rid of results that do not have fields I ask for. This evaluation is done post-filtering of edges as well.
see more about cascade here