I agree with flyburg.
RNAV is not RNP.
The header used to say RNAV (RNP) not RNAV(GPS or GNSS)
RNAV (GPS) is not the same as RNAV(RNP)
This is a very confusing an un-necessary designation for RNP. IF you have the cert for RNP, it should not be RNAV(GPS) which has a limit of RNP1.0.
That's not the case here. In the old days, we did GPS NPA approaches, and had an approval for such approaches (after pilot training in GNSS theory and doing 3 approaches under training).
When the RNP concept was formalised recently, our authority decided that the old GPS NPA approaches were equivalent to RNP APCH LNAV approaches ie RNP 0.3 required. The 0.3 was always the navigation performance required for our GPS NPAs anyway.
As far as training goes, the training for RNP APCH LNAV (and LNAV/VNAV [being Baro VNAV]) is the same as the old GPS NPA: theory course and 3 training approaches.
So to answer the OP's question, here you need Flight Manual authorisation and be trained in theory and 3 approaches before being authorised to conduct RNP APCH LNAV approaches.
The chart titles for our RNP APCH LNAV approaches are "RNAV-Z (GNSS) RWY 23".
The chart titles for RNP-AR approaches are "RNAV-U (RNP) RWY 23".
Its the whole crap with enroute and people not wanting to equip/train to RNP-AR.
From what I can see of the requirements for RNP-AR, I don't blame them.