If they're Sketchup components, I guess you want to use them as library objects. You have to save them in a format that Archicad reads, and then open them as objects (see AC help) and re-save in Archicad.
I think to save them as 3DS in Sketchup works best, but DWG format will do too. I think you need Sketchup Pro do do this.
AC4.1-AC26SWE; MacOS13.5.1; MP5,1+MBP16,1