If it is anything like the Bendix KLN94 GPS, it could be set up for VFR only use , or IFR use without approach capability or full IFR capability depending on how it was certified at install time and that will disable certain functionality. e.g. the KLN94 will display "GPS Approaches Disabled" if configured for VFR or IFR use without approach capability.
The KLN94 can be set like that, and indeed when I got my plane new, the UK CAA demanded it to be set to VFR only, despite the BRNAV approval being on the CAA approved Type Certificate
The UK dealer routinely reset them to IFR (which takes only minutes if you know how
).
I don't think the Garmin x30 units can be similarly configured. You get the whole lot on them - whatever is in the Jepp database.
However, to fly IFR (BRNAV) with any IFR GPS, the installation also need to comply with various regs. Simply screwing a GNS530 into the dash is not sufficient. One needs specified indicators within the pilot primary field of view.
BRNAV seems to have similar requirements to FAA AC20-138A which is the FAA approach certification requirement. On an EASA reg plane, or indeed a US reg one, you need a custom flight manual supplement to legally fly GPS approaches...