No...My understanding is that position is 2D
I think this is the second question in a week regarding the interpretation and setup for measurement to datums. Position tolerance can be 2D in very thin cross sections like a .0005" shim however if there is a 3D Datum Reference Frame then the interpretation of the geometric tolerance boundary for position (and others) is 3D.
My best and most practical answer is that you need significant training in the interpretation and application of datums and the perspective geometric tolerances.
I'm not going to attempt the train you in this forum as you need a lot of basics..
If you have a premium membership you can access my last book on ASME GD&T per. ASME Y14.5-2009 "Geometric Boundaries III, Interpretation and Application of GD&T per. ASME Y14.5-2009 and ASME Y14.41-2012".
You can also purchase my latest and greatest Geometric Boundaries IV on this website and have it delivered to your location.