Joomla usegrouplist Form Field Type
The usergrouplist form field type provides a dropdown select box of Joomla user groups. This field extends the list field type.
XML Field Definition
<field
name="usergroup"
type="usergrouplist"
label="User Group"
layout="joomla.form.field.list-fancy-select"
checksuperusergroup="1">
<option value="0">JSELECT</option>
</field>
Additional Parameters
checksuperusergroup: It is boolean to omit Super User groups. Values can be 1 or 0. The default value is 0, which means Super User group is displayed by default.