Find the minimum value within grouped data

Hello,

I need to replication a query that is done in access on a table within Powerbi. Im new to powerbi as well. 

So a little background first, i am reporting on a Help Desk ticking system. This system is home grown and only have access to certian sub-sets of records. 

1 of these tables is "StaffActions" basically a record of every single action that occurs on a help desk ticket, for all tickets that were actioned on. 

For every IncidentNo, there are multiple unique ActionID. These ActionID has an associated Action Description, ActionDateTime. 

I need to filter only actions that the ActionDescription has "Incident assigned to:*" (Notice the wild card) 

Now most incidents eventually have multiple "Incidents assigned to:*" records. Since they get escalated and bounced around to different engineers. 

I then need to find the ActionDateTime of the earliest record for each IncidentNo in the table. 

I can do it in Access using the below query:

I spent several hours trying to figure out how to do this in a calculated column, or calcutlated table and no luck. 

End result is I will compare the "FristActionDateTime" for each ticket to the tickets OpenDateTime to find out how long each time waited in the queue before its first assignment. 

Any ideas, is this even possible with PowerBi?