If you have the citation of a reported case, try searching the UBC Library catalogue by entering the abbreviation for the law report series (e.g., BCLR) into the search box to find the location and call number. If this method does not work, refer to the table of abbreviations in the first volume of the Canadian Abridgment, located at LAW LIBRARY reference room (level 2): KE173 .C364 2003. Once you know the full title of the law report series, search for the location and call number in the catalogue.
Example: For Rooney v Chan (1992), 76 BCLR 186, a title search in the catalogue for BCLR indicates that the British Columbia Law Reports have the call number LAW LIBRARY level 4: KEB104 .A24. Most law reports are located on level 4 of the library. Once you get to the set of the BCLR, look for volume 76. The case Rooney v Chan will be found on page 186.
If the case you are looking for is a recent unreported decision from B.C., you can likely get a copy of it by using CanLII, the Canadian Legal Information Institute website. Search by the name of the case or the citation.