how to save selected

I m wondering how to save selected objects as a different file ?

I know selecting invert then save the file then again open the file select different ones again invert and save… & on & on…
what if I want to save multiple segmented files from a large single file from blender?

Collect the objects you want to save into groups. Then in new files append or link the groups into it.

on win you can always have 2 files open
and copy then paste your selected objects

happy bl