There are many examples if you simply search the forum however for a quick start you can use below session relevance, it can be used for creating custom reporting or within API query:
(ID of parent group of actions of it as string | "N/A", ID of Actions of it as string | "N/A", name of parent group of actions of it as string | "N/A", name of action of it as string, Name of Computers of it as string | "N/A", Status of it as string | "N/A", State of Actions of it as string | "N/A", Time Issued of action of it as string, start time of it as string | "N/A", end time of it as string | "N/A") of results of member actions of bes actions whose (id of it = MAG_ID)
Related similar post for Custom Reporting:
We want Patch Report - Reporting - BigFix Forum
If you are interested action status report based on any computer group:
Relevance - action status report group membership - Content Authoring - BigFix Forum