Checkbox Box Groups can be populated by Keywords , XML Applications, Database table, or static lists. To get the label for the selected values in the Check Box Group you can us the $rx.keyword.getChoiceLabel method.
To get the values and labels, selected in a check box group field the following code can be used:
$sys.item.getProperty("rx:checkboxgroupfieldname")
#set($allValues = $sys.item.getProperty("rx:checkboxgroupfieldname").getValues())
#foreach($thisValue in $allValues)
<br/>
Value: $thisValue.String
<br/>
Label: $rx.keyword.getChoiceLabel("contenttypename","checkboxgroupfieldname",$thisValue.String)##
<br/>
<hr/>
#end