Prior to v2.6.0 of Wireshark, filter buttons were created in the preferences file. Beginning with v2.6.0, new filter buttons are created in the dfilter_buttons file. However, the later versions of Wireshark still recognize filter buttons that were created by earlier versions and that are in the preferences file. If some of your buttons were created before upgrading to v2.6.0, and some created after upgrading, you will have filter buttons in both places.
If you are using v2.6.0 of Wireshark or later, but all of your filter buttons were created by earlier versions and are in the preferences file, Wireshark will not show a path and file name on the Filter Buttons dialog. Wireshark will only show the path and file name when at least one button has been created using v2.6.0 or later, which causes the dfilter_buttons file to be created. And it will only show the path and file name of the dfilter_buttons file; it will not also list the preferences file.
To avoid confusion, I recommend deleting any filter buttons that are in the preferences file and then recreating them, which will put them in the dfilter_buttons file. This way, all of your filter buttons will be in one location. You could also cut and paste from one file to the other, but you will have to do some editing. Each filter button is three lines in the preferences file, but only one line in the dfilter_buttons file. The format used in each file is obvious, though.
