I'am try to figure out on how can I administer user account on a certain ins

Hello Jessica,

To get a list of all Active User in the system you can use the following Expression:

1) Create a Custom Group, that has all the users in it. You can add a Membership Rule to the custom Group you created to Import all users who username = * (wildcard)
2) Create a Constant of type "Group", cons!ALL_USERS_CUSTOM and point the constant to the Custom Group your created
3) Create the following expression to get all users from this custom group:
=getdistinctusers(topeople(cons!ALL_USERS_CUSTOM))

Hi Alok, how do you get a list of deactivated users though?

Take a look at the User Search Expressions from the Shared Components to get this list.
forum.appian.com/.../summary

You can use the getdeactivatedusersby() function to obtain this list:
=getdeactivatedusersby("username","",2)