It's actually not just 上, it's the grammar pattern「Aする上で」. 「Aする上で」means something like "When doing A".
So your sentence means something like "The fact that I have had a very rich experience will be very beneficial (a lifetime treasure?) for my future life!"
Though the lack of context makes this sentence a bit weird.
Here are some example sentences from yourei.jp :
Therefore, if you're bad at English, the degree of freedom in creating experiments (when creating experiments) will be limited.
Again, let's not forget this when trying to understand Western European civilization.
Basically, the following three concepts are used to explain (when explaining) animal welfare.
Of course, the brain is an important organ that becomes a "hub" in percepting (when percepting) the world.
As you can see する上で can also be followed by の if there's a noun after it.