When right clicking a file in K3B and clicking
Open File Manager it attempts to open the file in Sublime Text (my default text editor). I need it to open in Nemo (my default file manager). Is there a way to change this setting?
k3b uses the default file manager for KDE. Make sure that Nemo is set as your default file manager:
Files should now open up using Nemo when you right click a file from k3b and choose Open File Manager.