In this case, you'll create just one AD Group, this AD Groups will contain a list of 100 users.
Once that the AD Groups has been created with the users assigned, go to the QMC, edit the dashboard's task that you need to grant the access for this AD Group and add it in the PDL.
Use the same AD Group in the PDL for each dashboard that you need. Just remember that every time that you need add a new user, you must edit the AD Group.