Yes. What you want to do is use the 'replace' composite option, and then use the numeric control next to the composite popup to adjust the layer transparency. You will notice that all the transparency numerics default to 100%.
You will also need to have the View popup set to 'All Layers' to see an effect, since when the View is set to 'Current Layer' you are just looking at the current layer only so there is no compositing taking place.
The term compositing refers to an algorithm that takes 2 different images as input and outputs one 'composited' image. So what you are referring to as 'mode' we are referring to as 'composite' in studio artist. Some of the specific compositing operations in studio artist are similar to ones in other programs but there are some unique ones as well.
Thanks for your detailed explanation. I think understanding of the uniqe of SA is the first step to learn this tool rapidly. Studio Artist seems to be a tree have a lot of branches. and incredible thing is each one of branches grow up to the uniqe way.