if you have upgraded to VectorWorks 2008 you might be looking for the Create Layer Link... command. If you are using VectorWorks Fundamentals you will find it, but not if you are using VectorWorks Architect or Landmark or any of the other flavours of VectorWorks. That’s because the command is not longer in the same place, in fact the command has been removed from the menu bar al together.
Instead of a layer link use a Design Layer Viewport (DLVP). The DVLP is similar to a layer link when you use it, but it is much more powerful. In VectorWorks 2008 you can crop layer links, but with a DLVP you can turn classes or layers on and off and change the graphic style of classes/