diff --git a/app/apps/common/widgets/tom_select.py b/app/apps/common/widgets/tom_select.py
index 399637d..6de3a73 100644
--- a/app/apps/common/widgets/tom_select.py
+++ b/app/apps/common/widgets/tom_select.py
@@ -14,6 +14,7 @@ class TomSelect(widgets.Select):
         clear_text=_("Clear"),
         no_results_text=_("No results..."),
         checkboxes=False,
+        group_by=None,
         *args,
         **kwargs
     ):
@@ -26,6 +27,7 @@ class TomSelect(widgets.Select):
         self.clear_text = clear_text
         self.no_results_text = no_results_text
         self.checkboxes = checkboxes
+        self.group_by = group_by
 
     def build_attrs(self, base_attrs, extra_attrs=None):
         attrs = super().build_attrs(base_attrs, extra_attrs)
@@ -49,6 +51,81 @@ class TomSelect(widgets.Select):
 
         return attrs
 
+    def optgroups(self, name, value, attrs=None):
+        if not self.group_by:
+            # If no group_by is set, return all options as a single list without optgroups
+            return [
+                (
+                    None,
+                    [
+                        self.create_option(
+                            name,
+                            option_value,
+                            option_label,
+                            (str(option_value) in value),
+                            index,
+                            subindex=None,
+                            attrs=attrs,
+                        )
+                        for index, (option_value, option_label) in enumerate(
+                            self.choices
+                        )
+                    ],
+                    0,
+                )
+            ]
+
+        groups = {}
+        has_selected = False
+        value = set(value) if value else set()
+
+        for index, (option_value, option_label) in enumerate(self.choices):
+            if option_value is None:
+                option_value = ""
+
+            # Determine the group key
+            if hasattr(option_value, "instance") and hasattr(
+                option_value.instance, self.group_by
+            ):
+                group_key = getattr(option_value.instance, self.group_by) or _(
+                    "Ungrouped"
+                )
+            else:
+                group_key = _("Ungrouped")
+
+            group_name = str(group_key) if group_key is not None else None
+
+            if isinstance(option_label, (list, tuple)):
+                choices = option_label
+            else:
+                choices = [(option_value, option_label)]
+
+            if group_name not in groups:
+                groups[group_name] = []
+
+            for subvalue, sublabel in choices:
+                selected = (not has_selected or self.allow_multiple_selected) and str(
+                    subvalue
+                ) in value
+                has_selected |= selected
+                groups[group_name].append(
+                    self.create_option(
+                        name,
+                        subvalue,
+                        sublabel,
+                        selected,
+                        index,
+                        subindex=None,
+                        attrs=attrs,
+                    )
+                )
+
+        optgroups = []
+        for group_name, subgroup in groups.items():
+            optgroups.append((group_name, subgroup, 0))
+
+        return optgroups
+
 
 class TomSelectMultiple(SelectMultiple, TomSelect):
     pass