Hello Lars,
Very much like you, I am new to the list (albeit not entirely new to Inkscape itself).
If Inkscape allows for user scripting, however, which I am not sure if it does,
(Edit) I had to google and I found a blog post titled "Inkscape extensions by non developers, for non developers. A primer". The post explains it is possible.
To avoid breaking the url across lines, I decided to shorten it, so see https://goo.gl/Fr2Mre to read how non-developers like you and me could create an extension. It's a bit intimidating to think about it, but maybe it could be done by non-developers, I don't know.)
then an ordinary user could write a script (or extension) and make the process automatized.
Providing that the part you want to edit is selected, the extension would need to: a) create new layer and name it "1st temporary (layer)", b) move currently selection to the newly created temp layer, c) create another layer and name it for example "2nd temp (layer)", d) reverse the selection, e) move new selection (i.e. all but those in the 1st temp layer) to the second temp layer, f) lock and g) hide the 2nd temp layer,
This way we would be able to select and edit the parts from "1st temp layer" only, as you suggested.
Kind Regards, DyslexicAweTalent
P.S. To editors of the list. Maybe you want people who are new to the list, like me, to read the reminders how to contribute to the list, using a numbered list like that (just a humble proposal):
1) If sending a new submission, send it to inkscape-user@lists.sourceforge.net
2) If replying, the Subject line should be changed from generic "XXX digest" to a "Re:" and more specific subject.
Date: 30 Jan 2017 15:41 From: "Lars" <noreply@...3267...> Subject: Edit particular part of SVG only
Say an SVG file has a chair. The chair is composed of several parts. It has a back, legs, etc. Can one part be completely isolated?