The average of the two highest per group

[cptcherry]

HI there,

Here is my data:

Once I sort out the grouping situation (to group by datetime within 2 minutes grouping) (see: https://community.powerbi.com/t5/Power-Query/Grouping-date-times-that-are-within-a-minute-of-the-val... )

For each group, I'd want to average the two highest values from the strength column.

How can I do that? Is it best done in Power Query, or in Dax?

[AlexisOlson · Accepted solution]

My answer here may be useful:
https://community.powerbi.com/t5/Desktop/Filter-out-top-3-rows-based-on-same-timestamp/m-p/2159050

The key is using Group By along with Table.MaxN.