This location is currently listed on Tesla website as having 3 Tesla Wall Connectors, up to 22kW. At the end of 2019 I had recorded that the website listed 2 chargers, but I think it was an error and there have always been 3 chargers, as visible in older pictures of the location.
The Tesla chargers are no longer there. They have been replaced by ABB chargers networked through eCarUp. The pictures of old Tesla setup on Chargemap and GoingElectric show they were at the same location that now hosts the ABB chargers. The chargers at the 2 extremities (PP12 and 14) were Tesla only and the middle (PP13) was for all EVs.
Those older pictures show that there used to be a text "nur für gäste" in addition to the EV sign on the ground, but this text no longer exists today. There is still the ban sign on the wall saying it's a private parking. On the chargers there's a sticker with the eCarUp QR code and "Parking space to be paid separately", so maybe there's a possibility to charge here even if you are not a guest, if you pay for parking at the reception.
It's difficult to know for sure when the switch from Tesla to paid happened, but it was likely in 2022. The eCarUp chargers were visible on IchTankeStrom from 2022-05-13 IchTankeStrom. There's a comment on Chargemap from July 2022 that says the chargers are no longer Tesla.
On eCarUp there are 3 more connectors named Garagenplatz 4 to Garagenplatz 6. They appeared on IchTankeStrom at the same time as the other chargers. As the name suggests, those are probably indoor. I didn't see any other charger around the building. I didn't spot a garage entrance either but wasn't really looking for it.
The indoor chargers are cheaper on eCarUp. I wonder why they didn't set the same price, if parking is paid separately for both areas.