User from group not populating in drop-down of custom instantiation

System

Hi,

This seems to be a very basic thing. I have created a group in TS. Now i want to pull the users in the grp in the drop-down of the custom instantiation. However, for some reason I am not able to do it at the moment .
Please find below my code. Please let me know if the issue is happening because I am using "_" in my group name. I cannot think of any other possible reason.
Code:
<\inline command="Datasource:executeComponent:dd_image_approvers"/>

Thanks ,
Mav