I have a list of groups a user belongs to. Those names do not match the name of

Moritz,

I was browing through the custom functions in the Shared Components of Forum and there does not appear to be a way to get from group attribute to group. The same is true for the out of the box group function.

How have you received this list? If this was from another process in Appian, then you should make sure to save the group ID's or the groups themselves to better manage the group membership.

If the information is not from Appian, then you will need to create a custom function to achieve this.

I believe Michael is correct about needing to use a custom plugin to do this as currently described. However, I want to propose an alternative design that could avoid this problem. I realize it might be too late to redesign your app, but just food for thought.

Instead of using custom group attributes, you could store the extra metadata about groups in a database table. You could design processes to insert/update this data using Write to Data Store nodes and Paging Grids. The benefit of a process approach is that you could control who can update the groups without having to give users Designer access and you would have audit capability to know who changed a group.

If the data was in a database, it'd be easy to run a query rule to find all the group ids that matched the list of group attributes you have for a user. You wouldn't need a custom expression plugin for this.