diff --git a/gramps/gen/filters/rules/_rule.py b/gramps/gen/filters/rules/_rule.py
index f8d5859b6..63c9f3872 100644
--- a/gramps/gen/filters/rules/_rule.py
+++ b/gramps/gen/filters/rules/_rule.py
@@ -141,8 +141,10 @@ class Rule:
 
     def display_values(self):
         """Return the labels and values of this rule."""
-        l_v = ( '%s="%s"' % (_(self.labels[ix]), self.list[ix])
-                for ix in range(len(self.list)) if self.list[ix] )
+        l_v = ('%s="%s"' % (_(self.labels[ix][0] if
+                              isinstance(self.labels[ix], tuple) else
+                              self.labels[ix]), self.list[ix])
+               for ix in range(len(self.list)) if self.list[ix])
 
         return ';'.join(l_v)
 
diff --git a/gramps/gui/editors/filtereditor.py b/gramps/gui/editors/filtereditor.py
index e53eb5070..431b4b05d 100644
--- a/gramps/gui/editors/filtereditor.py
+++ b/gramps/gui/editors/filtereditor.py
@@ -501,7 +501,11 @@ class EditRule(ManagedWindow):
             grid.set_row_spacing(6)
             grid.show()
             for v in arglist:
-                l = Gtk.Label(label=v, halign=Gtk.Align.END)
+                if isinstance(v, tuple):
+                    # allows filter to create its own GUI element
+                    l = Gtk.Label(label=v[0], halign=Gtk.Align.END)
+                else:
+                    l = Gtk.Label(label=v, halign=Gtk.Align.END)
                 l.show()
                 if v == _('Place:'):
                     t = MyPlaces([])
@@ -585,6 +589,9 @@ class EditRule(ManagedWindow):
                 elif v == _('Units:'):
                     t = MyList([0, 1, 2],
                                [_('kilometers'), _('miles'), _('degrees')])
+                elif isinstance(v, tuple):
+                    # allow filter to create its own GUI element
+                    t = v[1](self.db)
                 else:
                     t = MyEntry()
                 t.set_hexpand(True)