Kenneth Fisher shows how to find the min and max values for a partition:
So what does it do? Per BOL
Returns the partition number into which a set of partitioning column values would be mapped for any specified partition function in SQL Server 2016.
So it basically tells us which partition any given row is in. This can be particularly handy at times. For example, if you want to know the min and max values of a column per partition.
Read on for a couple scripts which use $Partition.