So if you have 1000 accounts, you would like to have 1000 records in your navigation pane?
That seems impractical and there is no way to do it either, as you can not have a dynamic navigation pane.
Instead look at using Global search in CRM 2015 and teach the users how to use that.
Rune Daub Senior Consultant - Dynateam CRM http://www.dynateam.dk