Whether you import or link geometry from other sources, you should understand how the geometry behaves in Revit and what determines whether the geometry can be cut in a plan or section view.
In Revit, an object must be assigned a category in order for Revit to know how to cut it, whether in plan or section.
Geometry in a 3D DWG file imported or linked directly into a Revit model has no category assigned, and therefore will not be cut. For example, if you create a level at the elevation of a typical wall and then switch to a plan view, the imported geometry will not cut at that level. However, if you import the geometry into a cuttable family category (such as Generic Models), the geometry will cut in accordance with Revit’s cut planes.
To do this, you can use an in-place family from within a model, or create a new loadable family.
Import (you cannot use Link) your 3D DWG geometry into the family. You can use any of the cuttable family categories, but most likely the Generic Models category will meet your needs. After you load the family into the project, the imported geometry will cut according to the object styles assigned to the category used.
When you import 3D shapes from SAT files or 3DM files, you assign categories to the geometry. These 3D shapes adopt the behavior of the assigned Revit categories, including their cutting characteristics. See About Importing 3D Shapes.