Revit files have a certain structure when imported into Navisworks. The categories and sub-categories are listed per level. This makes it very easy to do takeoffs.
Civil 3D files have a different structure. Objects are arranged by the containing layers. They are not as easy to interpret as Revit files in Navisworks.
Inventor Files also have their own structure that is exposed.
The structure of FBX files is even more opaque.
There are so many files that Navisworks can interpret. It makes it great for being able to do some clash detections, but it is not necessarily advantageous to the purpose it is to be used for in Navisworks.
Do yourself the favor of investigating the structure and the properties of files as they are interpreted by Navisworks. This will help inform your choice of software to stipulate in the BEP.
If you need help adopting BIM and Navisworks in your practice, please contact Micrographics so we may be of assistance.