I'm using Kubuntu 18.10 and have the default file manager, Dolphin, set up quite nicely with servers, favorites etc. in the sidebar.
Now, whenever I want to open a file or folder from within a program, this file picker opens:
Now, many programs open this file/folder picker instead of the Dolphin file picker:
EDIT: This happens for example in Sublime Text and Firefox. Preinstalled programs (e. g. Spectacle or Kate) seem to actually do display a Dolphin file picker!
Is there any way to replace this with the Dolphin file picker, or at least get my favorites etc. into whatever this program is?