Unless you have family members overseas who find themselves dispossessed of their homes and forced to flee because of war, insurrection, or general violence and lawlessness, it is unlikely you will have a need for a Refugee Lawyer. Of course, if you are already in Canada under a Refugee program, you may need the assistance of a Refugee Lawyer to obtain the necessary permits to work, study, and remain in Canada permanently.
Even if you have overseas family members who would qualify to enter Canada as refugees, hiring a Refugee Lawyer directly may not be your best option. Almost all lawyers who specialize exclusively in Refugee Law work for or with international aid agencies and the reason is that beyond just a knowledge of the Refugee Laws of countries like Canada, Refugee Lawyers need the resources of organizations like the United Nations to remove refugees from the circumstances in which they find themselves and get them onto airplanes to safe havens (like Canada). Your better option might be to coordinate with one of the aid agencies that is often on the ground in places where refugees gather to avoid conflicts.
However, if you have family members in dire or life-threatening circumstances overseas, have a way of communicating with them, and can afford to hire a lawyer, you may wish to consult with a Refugee Lawyer. Your ultimate objective, of course, will be to find a way for your family members to get to Canada as refugees. It is almost certain that there not be any way to guarantee this will happen, no matter how well-connected your Refugee Lawyer is.
Some Immigration Lawyers may also practice refugee law, however not all Immigration Lawyers will have knowledge in this field.